ref: 5c1feb0ef0b795e5de71e956f9ccddcd5c4b7f21
dir: /sys/src/cmd/python/Misc/HISTORY/
Python History
--------------
This file contains the release messages for previous Python releases.
As you read on you go back to the dark ages of Python's history.
======================================================================
What's New in Python 2.4 final?
===============================
*Release date: 30-NOV-2004*
Core and builtins
-----------------
- Bug 875692: Improve signal handling, especially when using threads, by
forcing an early re-execution of PyEval_EvalFrame() "periodic" code when
things_to_do is not cleared by Py_MakePendingCalls().
What's New in Python 2.4 (release candidate 1)
==============================================
*Release date: 18-NOV-2004*
Core and builtins
-----------------
- Bug 1061968: Fixes in 2.4a3 to address thread bug 1010677 reintroduced
the years-old thread shutdown race bug 225673. Numeric history lesson
aside, all bugs in all three reports are fixed now.
Library
-------
- Bug 1052242: If exceptions are raised by an atexit handler function an
attempt is made to execute the remaining handlers. The last exception
raised is re-raised.
- ``doctest``'s new support for adding ``pdb.set_trace()`` calls to
doctests was broken in a dramatic but shallow way. Fixed.
- Bug 1065388: ``calendar``'s ``day_name``, ``day_abbr``, ``month_name``,
and ``month_abbr`` attributes emulate sequences of locale-correct
spellings of month and day names. Because the locale can change at
any time, the correct spelling is recomputed whenever one of these is
indexed. In the worst case, the index may be a slice object, so these
recomputed every day or month name each time they were indexed. This is
much slower than necessary in the usual case, when the index is just an
integer. In that case, only the single spelling needed is recomputed
now; and, when the index is a slice object, only the spellings needed
by the slice are recomputed now.
- Patch 1061679: Added ``__all__`` to pickletools.py.
Build
-----
- Bug 1034277 / Patch 1035255: Remove compilation of core against CoreServices
and CoreFoundation on OS X. Involved removing PyMac_GetAppletScriptFile()
which has no known users. Thanks Bob Ippolito.
C API
-----
- The PyRange_New() function is deprecated.
What's New in Python 2.4 beta 2?
================================
*Release date: 03-NOV-2004*
License
-------
The Python Software Foundation changed the license under which Python
is released, to remove Python version numbers. There were no other
changes to the license. So, for example, wherever the license for
Python 2.3 said "Python 2.3", the new license says "Python". The
intent is to make it possible to refer to the PSF license in a more
durable way. For example, some people say they're confused by that
the Open Source Initiative's entry for the Python Software Foundation
License::
http://www.opensource.org/licenses/PythonSoftFoundation.php
says "Python 2.1.1" all over it, wondering whether it applies only
to Python 2.1.1.
The official name of the new license is the Python Software Foundation
License Version 2.
Core and builtins
-----------------
- Bug #1055820 Cyclic garbage collection was not protecting against that
calling a live weakref to a piece of cyclic trash could resurrect an
insane mutation of the trash if any Python code ran during gc (via
running a dead object's __del__ method, running another callback on a
weakref to a dead object, or via any Python code run in any other thread
that managed to obtain the GIL while a __del__ or callback was running
in the thread doing gc). The most likely symptom was "impossible"
``AttributeError`` exceptions, appearing seemingly at random, on weakly
referenced objects. The cure was to clear all weakrefs to unreachable
objects before allowing any callbacks to run.
- Bug #1054139 _PyString_Resize() now invalidates its cached hash value.
Extension Modules
-----------------
- Bug #1048870: the compiler now generates distinct code objects for
functions with identical bodies. This was producing confusing
traceback messages which pointed to the function where the code
object was first defined rather than the function being executed.
Library
-------
- Patch #1056967 changes the semantics of Template.safe_substitute() so that
no ValueError is raised on an 'invalid' match group. Now the delimiter is
returned.
- Bug #1052503 pdb.runcall() was not passing along keyword arguments.
- Bug #902037: XML.sax.saxutils.prepare_input_source() now combines relative
paths with a base path before checking os.path.isfile().
- The whichdb module can now be run from the command line.
- Bug #1045381: time.strptime() can now infer the date using %U or %W (week of
the year) when the day of the week and year are also specified.
- Bug #1048816: fix bug in Ctrl-K at start of line in curses.textpad.Textbox
- Bug #1017553: fix bug in tarfile.filemode()
- Patch #737473: fix bug that old source code is shown in tracebacks even if
the source code is updated and reloaded.
Build
-----
- Patch #1044395: --enable-shared is allowed in FreeBSD also.
What's New in Python 2.4 beta 1?
================================
*Release date: 15-OCT-2004*
Core and builtins
-----------------
- Patch #975056: Restartable signals were not correctly disabled on
BSD systems. Consistently use PyOS_setsig() instead of signal().
- The internal portable implementation of thread-local storage (TLS), used
by the ``PyGILState_Ensure()``/``PyGILState_Release()`` API, was not
thread-correct. This could lead to a variety of problems, up to and
including segfaults. See bug 1041645 for an example.
- Added a command line option, -m module, which searches sys.path for the
module and then runs it. (Contributed by Nick Coghlan.)
- The bytecode optimizer now folds tuples of constants into a single
constant.
- SF bug #513866: Float/long comparison anomaly. Prior to 2.4b1, when
an integer was compared to a float, the integer was coerced to a float.
That could yield spurious overflow errors (if the integer was very
large), and to anomalies such as
``long(1e200)+1 == 1e200 == long(1e200)-1``. Coercion to float is no
longer performed, and cases like ``long(1e200)-1 < 1e200``,
``long(1e200)+1 > 1e200`` and ``(1 << 20000) > 1e200`` are computed
correctly now.
Extension modules
-----------------
- ``collections.deque`` objects didn't play quite right with garbage
collection, which could lead to a segfault in a release build, or
an assert failure in a debug build. Also, added overflow checks,
better detection of mutation during iteration, and shielded deque
comparisons from unusual subclass overrides of the __iter__() method.
Library
-------
- Patch 1046644: distutils build_ext grew two new options - --swig for
specifying the swig executable to use, and --swig-opts to specify
options to pass to swig. --swig-opts="-c++" is the new way to spell
--swig-cpp.
- Patch 983206: distutils now obeys environment variable LDSHARED, if
it is set.
- Added Peter Astrand's subprocess.py module. See PEP 324 for details.
- time.strptime() now properly escapes timezones and all other locale-specific
strings for regex-specific symbols. Was breaking under Japanese Windows when
the timezone was specified as "Tokyo (standard time)".
Closes bug #1039270.
- Updates for the email package:
+ email.Utils.formatdate() grew a 'usegmt' argument for HTTP support.
+ All deprecated APIs that in email 2.x issued warnings have been removed:
_encoder argument to the MIMEText constructor, Message.add_payload(),
Utils.dump_address_pair(), Utils.decode(), Utils.encode()
+ New deprecations: Generator.__call__(), Message.get_type(),
Message.get_main_type(), Message.get_subtype(), the 'strict' argument to
the Parser constructor. These will be removed in email 3.1.
+ Support for Python earlier than 2.3 has been removed (see PEP 291).
+ All defect classes have been renamed to end in 'Defect'.
+ Some FeedParser fixes; also a MultipartInvariantViolationDefect will be
added to messages that claim to be multipart but really aren't.
+ Updates to documentation.
- re's findall() and finditer() functions now take an optional flags argument
just like the compile(), search(), and match() functions. Also, documented
the previously existing start and stop parameters for the findall() and
finditer() methods of regular expression objects.
- rfc822 Messages now support iterating over the headers.
- The (undocumented) tarfile.Tarfile.membernames has been removed;
applications should use the getmember function.
- httplib now offers symbolic constants for the HTTP status codes.
- SF bug #1028306: Trying to compare a ``datetime.date`` to a
``datetime.datetime`` mistakenly compared only the year, month and day.
Now it acts like a mixed-type comparison: ``False`` for ``==``,
``True`` for ``!=``, and raises ``TypeError`` for other comparison
operators. Because datetime is a subclass of date, comparing only the
base class (date) members can still be done, if that's desired, by
forcing using of the approprate date method; e.g.,
``a_date.__eq__(a_datetime)`` is true if and only if the year, month
and day members of ``a_date`` and ``a_datetime`` are equal.
- bdist_rpm now supports command line options --force-arch,
{pre,post}-install, {pre,post}-uninstall, and
{prep,build,install,clean,verify}-script.
- SF patch #998993: The UTF-8 and the UTF-16 stateful decoders now support
decoding incomplete input (when the input stream is temporarily exhausted).
``codecs.StreamReader`` now implements buffering, which enables proper
readline support for the UTF-16 decoders. ``codecs.StreamReader.read()``
has a new argument ``chars`` which specifies the number of characters to
return. ``codecs.StreamReader.readline()`` and
``codecs.StreamReader.readlines()`` have a new argument ``keepends``.
Trailing "\n"s will be stripped from the lines if ``keepends`` is false.
- The documentation for doctest is greatly expanded, and now covers all
the new public features (of which there are many).
- ``doctest.master`` was put back in, and ``doctest.testmod()`` once again
updates it. This isn't good, because every ``testmod()`` call
contributes to bloating the "hidden" state of ``doctest.master``, but
some old code apparently relies on it. For now, all we can do is
encourage people to stitch doctests together via doctest's unittest
integration features instead.
- httplib now handles ipv6 address/port pairs.
- SF bug #1017864: ConfigParser now correctly handles default keys,
processing them with ``ConfigParser.optionxform`` when supplied,
consistent with the handling of config file entries and runtime-set
options.
- SF bug #997050: Document, test, & check for non-string values in
ConfigParser. Moved the new string-only restriction added in
rev. 1.65 to the SafeConfigParser class, leaving existing
ConfigParser & RawConfigParser behavior alone, and documented the
conditions under which non-string values work.
Build
-----
- Building on darwin now includes /opt/local/include and /opt/local/lib for
building extension modules. This is so as to include software installed as
a DarwinPorts port <http://darwinports.opendarwin.org/>
- pyport.h now defines a Py_IS_NAN macro. It works as-is when the
platform C computes true for ``x != x`` if and only if X is a NaN.
Other platforms can override the default definition with a platform-
specific spelling in that platform's pyconfig.h. You can also override
pyport.h's default Py_IS_INFINITY definition now.
C API
-----
- SF patch 1044089: New function ``PyEval_ThreadsInitialized()`` returns
non-zero if PyEval_InitThreads() has been called.
- The undocumented and unused extern int ``_PyThread_Started`` was removed.
- The C API calls ``PyInterpreterState_New()`` and ``PyThreadState_New()``
are two of the very few advertised as being safe to call without holding
the GIL. However, this wasn't true in a debug build, as bug 1041645
demonstrated. In a debug build, Python redirects the ``PyMem`` family
of calls to Python's small-object allocator, to get the benefit of
its extra debugging capabilities. But Python's small-object allocator
isn't threadsafe, relying on the GIL to avoid the expense of doing its
own locking. ``PyInterpreterState_New()`` and ``PyThreadState_New()``
call the platform ``malloc()`` directly now, regardless of build type.
- PyLong_AsUnsignedLong[Mask] now support int objects as well.
- SF patch #998993: ``PyUnicode_DecodeUTF8Stateful`` and
``PyUnicode_DecodeUTF16Stateful`` have been added, which implement stateful
decoding.
Tests
-----
- test__locale ported to unittest
Mac
---
- ``plistlib`` now supports non-dict root objects. There is also a new
interface for reading and writing plist files: ``readPlist(pathOrFile)``
and ``writePlist(rootObject, pathOrFile)``
Tools/Demos
-----------
- The text file comparison scripts ``ndiff.py`` and ``diff.py`` now
read the input files in universal-newline mode. This spares them
from consuming a great deal of time to deduce the useless result that,
e.g., a file with Windows line ends and a file with Linux line ends
have no lines in common.
What's New in Python 2.4 alpha 3?
=================================
*Release date: 02-SEP-2004*
Core and builtins
-----------------
- SF patch #1007189: ``from ... import ...`` statements now allow the name
list to be surrounded by parentheses.
- Some speedups for long arithmetic, thanks to Trevor Perrin. Gradeschool
multiplication was sped a little by optimizing the C code. Gradeschool
squaring was sped by about a factor of 2, by exploiting that about half
the digit products are duplicates in a square. Because exponentiation
uses squaring often, this also speeds long power. For example, the time
to compute 17**1000000 dropped from about 14 seconds to 9 on my box due
to this much. The cutoff for Karatsuba multiplication was raised,
since gradeschool multiplication got quicker, and the cutoff was
aggressively small regardless. The exponentiation algorithm was switched
from right-to-left to left-to-right, which is more efficient for small
bases. In addition, if the exponent is large, the algorithm now does
5 bits (instead of 1 bit) at a time. That cut the time to compute
17**1000000 on my box in half again, down to about 4.5 seconds.
- OverflowWarning is no longer generated. PEP 237 scheduled this to
occur in Python 2.3, but since OverflowWarning was disabled by default,
nobody realized it was still being generated. On the chance that user
code is still using them, the Python builtin OverflowWarning, and
corresponding C API PyExc_OverflowWarning, will exist until Python 2.5.
- Py_InitializeEx has been added.
- Fix the order of application of decorators. The proper order is bottom-up;
the first decorator listed is the last one called.
- SF patch #1005778. Fix a seg fault if the list size changed while
calling list.index(). This could happen if a rich comparison function
modified the list.
- The ``func_name`` (a.k.a. ``__name__``) attribute of user-defined
functions is now writable.
- code_new (a.k.a new.code()) now checks its arguments sufficiently
carefully that passing them on to PyCode_New() won't trigger calls
to Py_FatalError() or PyErr_BadInternalCall(). It is still the case
that the returned code object might be entirely insane.
- Subclasses of string can no longer be interned. The semantics of
interning were not clear here -- a subclass could be mutable, for
example -- and had bugs. Explicitly interning a subclass of string
via intern() will raise a TypeError. Internal operations that attempt
to intern a string subclass will have no effect.
- Bug 1003935: xrange() could report bogus OverflowErrors. Documented
what xrange() intends, and repaired tests accordingly.
Extension modules
-----------------
- difflib now supports HTML side-by-side diff.
- os.urandom has been added for systems that support sources of random
data.
- Patch 1012740: truncate() on a writeable cStringIO now resets the
position to the end of the stream. This is consistent with the original
StringIO module and avoids inadvertently resurrecting data that was
supposed to have been truncated away.
- Added socket.socketpair().
- Added CurrentByteIndex, CurrentColumnNumber, CurrentLineNumber
members to xml.parsers.expat.XMLParser object.
- The mpz, rotor, and xreadlines modules, all deprecated in earlier
versions of Python, have now been removed.
Library
-------
- Patch #934356: if a module defines __all__, believe that rather than using
heuristics for filtering out imported names.
- Patch #941486: added os.path.lexists(), which returns True for broken
symlinks, unlike os.path.exists().
- the random module now uses os.urandom() for seeding if it is available.
Added a new generator based on os.urandom().
- difflib and diff.py can now generate HTML.
- bdist_rpm now includes version and release in the BuildRoot, and
replaces - by ``_`` in version and release.
- distutils build/build_scripts now has an -e option to specify the
path to the Python interpreter for installed scripts.
- PEP 292 classes Template and SafeTemplate are added to the string module.
- tarfile now generates GNU tar files by default.
- HTTPResponse has now a getheaders method.
- Patch #1006219: let inspect.getsource handle '@' decorators. Thanks Simon
Percivall.
- logging.handlers.SMTPHandler.date_time has been removed;
the class now uses email.Utils.formatdate to generate the time stamp.
- A new function tkFont.nametofont was added to return an existing
font. The Font class constructor now has an additional exists argument
which, if True, requests to return/configure an existing font, rather
than creating a new one.
- Updated the decimal package's min() and max() methods to match the
latest revision of the General Decimal Arithmetic Specification.
Quiet NaNs are ignored and equal values are sorted based on sign
and exponent.
- The decimal package's Context.copy() method now returns deep copies.
- Deprecated sys.exitfunc in favor of the atexit module. The sys.exitfunc
attribute will be kept around for backwards compatibility and atexit
will just become the one preferred way to do it.
- patch #675551: Add get_history_item and replace_history_item functions
to the readline module.
- bug #989672: pdb.doc and the help messages for the help_d and help_u methods
of the pdb.Pdb class gives have been corrected. d(own) goes to a newer
frame, u(p) to an older frame, not the other way around.
- bug #990669: os.path.realpath() will resolve symlinks before normalizing the
path, as normalizing the path may alter the meaning of the path if it
contains symlinks.
- bug #851123: shutil.copyfile will raise an exception when trying to copy a
file onto a link to itself. Thanks Gregory Ball.
- bug #570300: Fix inspect to resolve file locations using os.path.realpath()
so as to properly list all functions in a module when the module itself is
reached through a symlink. Thanks Johannes Gijsbers.
- doctest refactoring continued. See the docs for details. As part of
this effort, some old and little- (never?) used features are now
deprecated: the Tester class, the module is_private() function, and the
isprivate argument to testmod(). The Tester class supplied a feeble
"by hand" way to combine multiple doctests, if you knew exactly what
you were doing. The newer doctest features for unittest integration
already did a better job of that, are stronger now than ever, and the
new DocTestRunner class is a saner foundation if you want to do it by
hand. The "private name" filtering gimmick was a mistake from the
start, and testmod() changed long ago to ignore it by default. If
you want to filter out tests, the new DocTestFinder class can be used
to return a list of all doctests, and you can filter that list by
any computable criteria before passing it to a DocTestRunner instance.
- Bug #891637, patch #1005466: fix inspect.getargs() crash on def foo((bar)).
Tools/Demos
-----------
- IDLE's shortcut keys for windows are now case insensitive so that
Control-V works the same as Control-v.
- pygettext.py: Generate POT-Creation-Date header in ISO format.
Build
-----
- Backward incompatibility: longintrepr.h now triggers a compile-time
error if SHIFT (the number of bits in a Python long "digit") isn't
divisible by 5. This new requirement allows simple code for the new
5-bits-at-a-time long_pow() implementation. If necessary, the
restriction could be removed (by complicating long_pow(), or by
falling back to the 1-bit-at-a-time algorithm), but there are no
plans to do so.
- bug #991962: When building with --disable-toolbox-glue on Darwin no
attempt to build Mac-specific modules occurs.
- The --with-tsc flag to configure to enable VM profiling with the
processor's timestamp counter now works on PPC platforms.
- patch #1006629: Define _XOPEN_SOURCE to 500 on Solaris 8/9 to match
GCC's definition and avoid redefinition warnings.
- Detect pthreads support (provided by gnu pth pthread emulation) on
GNU/k*BSD systems.
- bug #1005737, #1007249: Fixed several build problems and warnings
found on old/legacy C compilers of HP-UX, IRIX and Tru64.
C API
-----
..
Documentation
-------------
- patch #1005936, bug #1009373: fix index entries which contain
an underscore when viewed with Acrobat.
- bug #990669: os.path.normpath may alter the meaning of a path if
it contains symbolic links. This has been documented in a comment
since 1992, but is now in the library reference as well.
New platforms
-------------
- FreeBSD 6 is now supported.
Tests
-----
..
Windows
-------
- Boosted the stack reservation for python.exe and pythonw.exe from
the default 1MB to 2MB. Stack frames under VC 7.1 for 2.4 are enough
bigger than under VC 6.0 for 2.3.4 that deeply recursive progams
within the default sys.getrecursionlimit() default value of 1000 were
able to suffer undetected C stack overflows. The standard test program
test_compiler was one such program. If a Python process on Windows
"just vanishes" without a trace, and without an error message of any
kind, but with an exit code of 128, undetected stack overflow may be
the problem.
Mac
---
..
What's New in Python 2.4 alpha 2?
=================================
*Release date: 05-AUG-2004*
Core and builtins
-----------------
- Patch #980695: Implements efficient string concatenation for statements
of the form s=s+t and s+=t. This will vary across implementations.
Accordingly, the str.join() method is strongly preferred for performance
sensitive code.
- PEP-0318, Function Decorators have been added to the language. These are
implemented using the Java-style @decorator syntax, like so::
@staticmethod
def foo(bar):
(The PEP needs to be updated to reflect the current state)
- When importing a module M raises an exception, Python no longer leaves M
in sys.modules. Before 2.4a2 it did, and a subsequent import of M would
succeed, picking up a module object from sys.modules reflecting as much
of the initialization of M as completed before the exception was raised.
Subsequent imports got no indication that M was in a partially-
initialized state, and the importers could get into arbitrarily bad
trouble as a result (the M they got was in an unintended state,
arbitrarily far removed from M's author's intent). Now subsequent
imports of M will continue raising exceptions (but if, for example, the
source code for M is edited between import attempts, then perhaps later
attempts will succeed, or raise a different exception).
This can break existing code, but in such cases the code was probably
working before by accident. In the Python source, the only case of
breakage discovered was in a test accidentally relying on a damaged
module remaining in sys.modules. Cases are also known where tests
deliberately provoking import errors remove damaged modules from
sys.modules themselves, and such tests will break now if they do an
unconditional del sys.modules[M].
- u'%s' % obj will now try obj.__unicode__() first and fallback to
obj.__str__() if no __unicode__ method can be found.
- Patch #550732: Add PyArg_VaParseTupleAndKeywords(). Analogous to
PyArg_VaParse(). Both are now documented. Thanks Greg Chapman.
- Allow string and unicode return types from .encode()/.decode()
methods on string and unicode objects. Added unicode.decode()
which was missing for no apparent reason.
- An attempt to fix the mess that is Python's behaviour with
signal handlers and threads, complicated by readline's behaviour.
It's quite possible that there are still bugs here.
- Added C macros Py_CLEAR and Py_VISIT to ease the implementation of
types that support garbage collection.
- Compiler now treats None as a constant.
- The type of values returned by __int__, __float__, __long__,
__oct__, and __hex__ are now checked. Returning an invalid type
will cause a TypeError to be raised. This matches the behavior of
Jython.
- Implemented bind_textdomain_codeset() in locale module.
- Added a workaround for proper string operations in BSDs. str.split
and str.is* methods can now work correctly with UTF-8 locales.
- Bug #989185: unicode.iswide() and unicode.width() is dropped and
the East Asian Width support is moved to unicodedata extension
module.
- Patch #941229: The source code encoding in interactive mode
now refers sys.stdin.encoding not just ISO-8859-1 anymore. This
allows for non-latin-1 users to write unicode strings directly.
Extension modules
-----------------
- cpickle now supports the same keyword arguments as pickle.
Library
-------
- Added new codecs and aliases for ISO_8859-11, ISO_8859-16 and
TIS-620
- Thanks to Edward Loper, doctest has been massively refactored, and
many new features were added. Full docs will appear later. For now
the doctest module comments and new test cases give good coverage.
The refactoring provides many hook points for customizing behavior
(such as how to report errors, and how to compare expected to actual
output). New features include a <BLANKLINE> marker for expected
output containing blank lines, options to produce unified or context
diffs when actual output doesn't match expectations, an option to
normalize whitespace before comparing, and an option to use an
ellipsis to signify "don't care" regions of output.
- Tkinter now supports the wish -sync and -use options.
- The following methods in time support passing of None: ctime(), gmtime(),
and localtime(). If None is provided, the current time is used (the
same as when the argument is omitted).
[SF bug 658254, patch 663482]
- nntplib does now allow to ignore a .netrc file.
- urllib2 now recognizes Basic authentication even if other authentication
schemes are offered.
- Bug #1001053. wave.open() now accepts unicode filenames.
- gzip.GzipFile has a new fileno() method, to retrieve the handle of the
underlying file object (provided it has a fileno() method). This is
needed if you want to use os.fsync() on a GzipFile.
- imaplib has two new methods: deleteacl and myrights.
- nntplib has two new methods: description and descriptions. They
use a more RFC-compliant way of getting a newsgroup description.
- Bug #993394. Fix a possible red herring of KeyError in 'threading' being
raised during interpreter shutdown from a registered function with atexit
when dummy_threading is being used.
- Bug #857297/Patch #916874. Fix an error when extracting a hard link
from a tarfile.
- Patch #846659. Fix an error in tarfile.py when using
GNU longname/longlink creation.
- The obsolete FCNTL.py has been deleted. The builtin fcntl module
has been available (on platforms that support fcntl) since Python
1.5a3, and all FCNTL.py did is export fcntl's names, after generating
a deprecation warning telling you to use fcntl directly.
- Several new unicode codecs are added: big5hkscs, euc_jis_2004,
iso2022_jp_2004, shift_jis_2004.
- Bug #788520. Queue.{get, get_nowait, put, put_nowait} have new
implementations, exploiting Conditions (which didn't exist at the time
Queue was introduced). A minor semantic change is that the Full and
Empty exceptions raised by non-blocking calls now occur only if the
queue truly was full or empty at the instant the queue was checked (of
course the Queue may no longer be full or empty by the time a calling
thread sees those exceptions, though). Before, the exceptions could
also be raised if it was "merely inconvenient" for the implementation
to determine the true state of the Queue (because the Queue was locked
by some other method in progress).
- Bugs #979794 and #980117: difflib.get_grouped_opcodes() now handles the
case of comparing two empty lists. This affected both context_diff() and
unified_diff(),
- Bug #980938: smtplib now prints debug output to sys.stderr.
- Bug #930024: posixpath.realpath() now handles infinite loops in symlinks by
returning the last point in the path that was not part of any loop. Thanks
AM Kuchling.
- Bug #980327: ntpath not handles compressing erroneous slashes between the
drive letter and the rest of the path. Also clearly handles UNC addresses now
as well. Thanks Paul Moore.
- bug #679953: zipfile.py should now work for files over 2 GB. The packed data
for file sizes (compressed and uncompressed) was being stored as signed
instead of unsigned.
- decimal.py now only uses signals in the IBM spec. The other conditions are
no longer part of the public API.
- codecs module now has two new generic APIs: encode() and decode()
which don't restrict the return types (unlike the unicode and
string methods of the same name).
- Non-blocking SSL sockets work again; they were broken in Python 2.3.
SF patch 945642.
- doctest unittest integration improvements:
o Improved the unitest test output for doctest-based unit tests
o Can now pass setUp and tearDown functions when creating
DocTestSuites.
- The threading module has a new class, local, for creating objects
that provide thread-local data.
- Bug #990307: when keep_empty_values is True, cgi.parse_qsl()
no longer returns spurious empty fields.
- Implemented bind_textdomain_codeset() in gettext module.
- Introduced in gettext module the l*gettext() family of functions,
which return translation strings encoded in the preferred encoding,
as informed by locale module's getpreferredencoding().
- optparse module (and tests) upgraded to Optik 1.5a1. Changes:
- Add expansion of default values in help text: the string
"%default" in an option's help string is expanded to str() of
that option's default value, or "none" if no default value.
- Bug #955889: option default values that happen to be strings are
now processed in the same way as values from the command line; this
allows generation of nicer help when using custom types. Can
be disabled with parser.set_process_default_values(False).
- Bug #960515: don't crash when generating help for callback
options that specify 'type', but not 'dest' or 'metavar'.
- Feature #815264: change the default help format for short options
that take an argument from e.g. "-oARG" to "-o ARG"; add
set_short_opt_delimiter() and set_long_opt_delimiter() methods to
HelpFormatter to allow (slight) customization of the formatting.
- Patch #736940: internationalize Optik: all built-in user-
targeted literal strings are passed through gettext.gettext(). (If
you want translations (.po files), they're not included with Python
-- you'll find them in the Optik source distribution from
http://optik.sourceforge.net/ .)
- Bug #878453: respect $COLUMNS environment variable for
wrapping help output.
- Feature #988122: expand "%prog" in the 'description' passed
to OptionParser, just like in the 'usage' and 'version' strings.
(This is *not* done in the 'description' passed to OptionGroup.)
C API
-----
- PyImport_ExecCodeModule() and PyImport_ExecCodeModuleEx(): if an
error occurs while loading the module, these now delete the module's
entry from sys.modules. All ways of loading modules eventually call
one of these, so this is an error-case change in semantics for all
ways of loading modules. In rare cases, a module loader may wish
to keep a module object in sys.modules despite that the module's
code cannot be executed. In such cases, the module loader must
arrange to reinsert the name and module object in sys.modules.
PyImport_ReloadModule() has been changed to reinsert the original
module object into sys.modules if the module reload fails, so that
its visible semantics have not changed.
- A large pile of datetime field-extraction macros is now documented,
thanks to Anthony Tuininga (patch #986010).
Documentation
-------------
- Improved the tutorial on creating types in C.
- point out the importance of reassigning data members before
assigning their values
- correct my misconception about return values from visitprocs. Sigh.
- mention the labor saving Py_VISIT and Py_CLEAR macros.
- Major rewrite of the math module docs, to address common confusions.
Tests
-----
- The test data files for the decimal test suite are now installed on
platforms that use the Makefile.
- SF patch 995225: The test file testtar.tar accidentally contained
CVS keywords (like $Id: HISTORY 43159 2006-03-20 06:30:41Z anthony.baxter $), which could cause spurious failures in
test_tarfile.py depending on how the test file was checked out.
What's New in Python 2.4 alpha 1?
=================================
*Release date: 08-JUL-2004*
Core and builtins
-----------------
- weakref.ref is now the type object also known as
weakref.ReferenceType; it can be subclassed like any other new-style
class. There's less per-entry overhead in WeakValueDictionary
objects now (one object instead of three).
- Bug #951851: Python crashed when reading import table of certain
Windows DLLs.
- Bug #215126. The locals argument to eval(), execfile(), and exec now
accept any mapping type.
- marshal now shares interned strings. This change introduces
a new .pyc magic.
- Bug #966623. classes created with type() in an exec(, {}) don't
have a __module__, but code in typeobject assumed it would always
be there.
- Python no longer relies on the LC_NUMERIC locale setting to be
the "C" locale; as a result, it no longer tries to prevent changing
the LC_NUMERIC category.
- Bug #952807: Unpickling pickled instances of subclasses of
datetime.date, datetime.datetime and datetime.time could yield insane
objects. Thanks to Jiwon Seo for a fix.
- Bug #845802: Python crashes when __init__.py is a directory.
- Unicode objects received two new methods: iswide() and width().
These query East Asian width information, as specified in Unicode
TR11.
- Improved the tuple hashing algorithm to give fewer collisions in
common cases. Fixes bug #942952.
- Implemented generator expressions (PEP 289). Coded by Jiwon Seo.
- Enabled the profiling of C extension functions (and builtins) - check
new documentation and modified profile and bdb modules for more details
- Set file.name to the object passed to open (instead of a new string)
- Moved tracebackobject into traceback.h and renamed to PyTracebackObject
- Optimized the byte coding for multiple assignments like "a,b=b,a" and
"a,b,c=1,2,3". Improves their speed by 25% to 30%.
- Limit the nested depth of a tuple for the second argument to isinstance()
and issubclass() to the recursion limit of the interpreter.
Fixes bug #858016 .
- Optimized dict iterators, creating separate types for each
and having them reveal their length. Also optimized the
methods: keys(), values(), and items().
- Implemented a newcode opcode, LIST_APPEND, that simplifies
the generated bytecode for list comprehensions and further
improves their performance (about 35%).
- Implemented rich comparisons for floats, which seems to make
comparisons involving NaNs somewhat less surprising when the
underlying C compiler actually implements C99 semantics.
- Optimized list.extend() to save memory and no longer create
intermediate sequences. Also, extend() now pre-allocates the
needed memory whenever the length of the iterable is known in
advance -- this halves the time to extend the list.
- Optimized list resize operations to make fewer calls to the system
realloc(). Significantly speeds up list appends, list pops,
list comprehensions, and the list constructor (when the input iterable
length is not known).
- Changed the internal list over-allocation scheme. For larger lists,
overallocation ranged between 3% and 25%. Now, it is a constant 12%.
For smaller lists (n<8), overallocation was upto eight elements. Now,
the overallocation is no more than three elements -- this improves space
utilization for applications that have large numbers of small lists.
- Most list bodies now get re-used rather than freed. Speeds up list
instantiation and deletion by saving calls to malloc() and free().
- The dict.update() method now accepts all the same argument forms
as the dict() constructor. This now includes item lists and/or
keyword arguments.
- Support for arbitrary objects supporting the read-only buffer
interface as the co_code field of code objects (something that was
only possible to create from C code) has been removed.
- Made omitted callback and None equivalent for weakref.ref() and
weakref.proxy(); the None case wasn't handled correctly in all
cases.
- Fixed problem where PyWeakref_NewRef() and PyWeakref_NewProxy()
assumed that initial existing entries in an object's weakref list
would not be removed while allocating a new weakref object. Since
GC could be invoked at that time, however, that assumption was
invalid. In a truly obscure case of GC being triggered during
creation for a new weakref object for an referent which already
has a weakref without a callback which is only referenced from
cyclic trash, a memory error can occur. This consistently created a
segfault in a debug build, but provided less predictable behavior in
a release build.
- input() builtin function now respects compiler flags such as
__future__ statements. SF patch 876178.
- Removed PendingDeprecationWarning from apply(). apply() remains
deprecated, but the nuisance warning will not be issued.
- At Python shutdown time (Py_Finalize()), 2.3 called cyclic garbage
collection twice, both before and after tearing down modules. The
call after tearing down modules has been disabled, because too much
of Python has been torn down then for __del__ methods and weakref
callbacks to execute sanely. The most common symptom was a sequence
of uninformative messages on stderr when Python shut down, produced
by threads trying to raise exceptions, but unable to report the nature
of their problems because too much of the sys module had already been
destroyed.
- Removed FutureWarnings related to hex/oct literals and conversions
and left shifts. (Thanks to Kalle Svensson for SF patch 849227.)
This addresses most of the remaining semantic changes promised by
PEP 237, except for repr() of a long, which still shows the trailing
'L'. The PEP appears to promise warnings for operations that
changed semantics compared to Python 2.3, but this is not
implemented; we've suffered through enough warnings related to
hex/oct literals and I think it's best to be silent now.
- For str and unicode objects, the ljust(), center(), and rjust()
methods now accept an optional argument specifying a fill
character other than a space.
- When method objects have an attribute that can be satisfied either
by the function object or by the method object, the function
object's attribute usually wins. Christian Tismer pointed out that
that this is really a mistake, because this only happens for special
methods (like __reduce__) where the method object's version is
really more appropriate than the function's attribute. So from now
on, all method attributes will have precedence over function
attributes with the same name.
- Critical bugfix, for SF bug 839548: if a weakref with a callback,
its callback, and its weakly referenced object, all became part of
cyclic garbage during a single run of garbage collection, the order
in which they were torn down was unpredictable. It was possible for
the callback to see partially-torn-down objects, leading to immediate
segfaults, or, if the callback resurrected garbage objects, to
resurrect insane objects that caused segfaults (or other surprises)
later. In one sense this wasn't surprising, because Python's cyclic gc
had no knowledge of Python's weakref objects. It does now. When
weakrefs with callbacks become part of cyclic garbage now, those
weakrefs are cleared first. The callbacks don't trigger then,
preventing the problems. If you need callbacks to trigger, then just
as when cyclic gc is not involved, you need to write your code so
that weakref objects outlive the objects they weakly reference.
- Critical bugfix, for SF bug 840829: if cyclic garbage collection
happened to occur during a weakref callback for a new-style class
instance, subtle memory corruption was the result (in a release build;
in a debug build, a segfault occurred reliably very soon after).
This has been repaired.
- Compiler flags set in PYTHONSTARTUP are now active in __main__.
- Added two builtin types, set() and frozenset().
- Added a reversed() builtin function that returns a reverse iterator
over a sequence.
- Added a sorted() builtin function that returns a new sorted list
from any iterable.
- CObjects are now mutable (on the C level) through PyCObject_SetVoidPtr.
- list.sort() now supports three keyword arguments: cmp, key, and reverse.
The key argument can be a function of one argument that extracts a
comparison key from the original record: mylist.sort(key=str.lower).
The reverse argument is a boolean value and if True will change the
sort order as if the comparison arguments were reversed. In addition,
the documentation has been amended to provide a guarantee that all sorts
starting with Py2.3 are guaranteed to be stable (the relative order of
records with equal keys is unchanged).
- Added test whether wchar_t is signed or not. A signed wchar_t is not
usable as internal unicode type base for Py_UNICODE since the
unicode implementation assumes an unsigned type.
- Fixed a bug in the cache of length-one Unicode strings that could
lead to a seg fault. The specific problem occurred when an earlier,
non-fatal error left an uninitialized Unicode object in the
freelist.
- The % formatting operator now supports '%F' which is equivalent to
'%f'. This has always been documented but never implemented.
- complex(obj) could leak a little memory if obj wasn't a string or
number.
- zip() with no arguments now returns an empty list instead of raising
a TypeError exception.
- obj.__contains__() now returns True/False instead of 1/0. SF patch
820195.
- Python no longer tries to be smart about recursive comparisons.
When comparing containers with cyclic references to themselves it
will now just hit the recursion limit. See SF patch 825639.
- str and unicode builtin types now have an rsplit() method that is
same as split() except that it scans the string from the end
working towards the beginning. See SF feature request 801847.
- Fixed a bug in object.__reduce_ex__ when using protocol 2. Failure
to clear the error when attempts to get the __getstate__ attribute
fail caused intermittent errors and odd behavior.
- buffer objects based on other objects no longer cache a pointer to
the data and the data length. Instead, the appropriate tp_as_buffer
method is called as necessary.
- fixed: if a file is opened with an explicit buffer size >= 1, repeated
close() calls would attempt to free() the buffer already free()ed on
the first call.
Extension modules
-----------------
- Added socket.getservbyport(), and make the second argument in
getservbyname() and getservbyport() optional.
- time module code that deals with input POSIX timestamps will now raise
ValueError if more than a second is lost in precision when the
timestamp is cast to the platform C time_t type. There's no chance
that the platform will do anything sensible with the result in such
cases. This includes ctime(), localtime() and gmtime(). Assorted
fromtimestamp() and utcfromtimestamp() methods in the datetime module
were also protected. Closes bugs #919012 and 975996.
- fcntl.ioctl now warns if the mutate flag is not specified.
- nt now properly allows to refer to UNC roots, e.g. in nt.stat().
- the weakref module now supports additional objects: array.array,
sre.pattern_objects, file objects, and sockets.
- operator.isMappingType() and operator.isSequenceType() now give
fewer false positives.
- socket.sslerror is now a subclass of socket.error . Also added
socket.error to the socket module's C API.
- Bug #920575: A problem where the _locale module segfaults on
nl_langinfo(ERA) caused by GNU libc's illegal NULL return is fixed.
- array objects now support the copy module. Also, their resizing
scheme has been updated to match that used for list objects. This improves
the performance (speed and memory usage) of append() operations.
Also, array.array() and array.extend() now accept any iterable argument
for repeated appends without needing to create another temporary array.
- cStringIO.writelines() now accepts any iterable argument and writes
the lines one at a time rather than joining them and writing once.
Made a parallel change to StringIO.writelines(). Saves memory and
makes suitable for use with generator expressions.
- time.strftime() now checks that the values in its time tuple argument
are within the proper boundaries to prevent possible crashes from the
platform's C library implementation of strftime(). Can possibly
break code that uses values outside the range that didn't cause
problems previously (such as sitting day of year to 0). Fixes bug
#897625.
- The socket module now supports Bluetooth sockets, if the
system has <bluetooth/bluetooth.h>
- Added a collections module containing a new datatype, deque(),
offering high-performance, thread-safe, memory friendly appends
and pops on either side of the deque.
- Several modules now take advantage of collections.deque() for
improved performance: Queue, mutex, shlex, threading, and pydoc.
- The operator module has two new functions, attrgetter() and
itemgetter() which are useful for creating fast data extractor
functions for map(), list.sort(), itertools.groupby(), and
other functions that expect a function argument.
- socket.SHUT_{RD,WR,RDWR} was added.
- os.getsid was added.
- The pwd module incorrectly advertised its struct type as
struct_pwent; this has been renamed to struct_passwd. (The old name
is still supported for backwards compatibility.)
- The xml.parsers.expat module now provides Expat 1.95.7.
- socket.IPPROTO_IPV6 was added.
- readline.clear_history was added.
- select.select() now accepts sequences for its first three arguments.
- cStringIO now supports the f.closed attribute.
- The signal module now exposes SIGRTMIN and SIGRTMAX (if available).
- curses module now supports use_default_colors(). [patch #739124]
- Bug #811028: ncurses.h breakage on FreeBSD/MacOS X
- Bug #814613: INET_ADDRSTRLEN fix needed for all compilers on SGI
- Implemented non-recursive SRE matching scheme (#757624).
- Implemented (?(id/name)yes|no) support in SRE (#572936).
- random.seed() with no arguments or None uses time.time() as a default
seed. Modified to match Py2.2 behavior and use fractional seconds so
that successive runs are more likely to produce different sequences.
- random.Random has a new method, getrandbits(k), which returns an int
with k random bits. This method is now an optional part of the API
for user defined generators. Any generator that defines genrandbits()
can now use randrange() for ranges with a length >= 2**53. Formerly,
randrange would return only even numbers for ranges that large (see
SF bug #812202). Generators that do not define genrandbits() now
issue a warning when randrange() is called with a range that large.
- itertools has a new function, groupby() for aggregating iterables
into groups sharing the same key (as determined by a key function).
It offers some of functionality of SQL's groupby keyword and of
the Unix uniq filter.
- itertools now has a new tee() function which produces two independent
iterators from a single iterable.
- itertools.izip() with no arguments now returns an empty iterator instead
of raising a TypeError exception.
- Fixed #853061: allow BZ2Compressor.compress() to receive an empty string
as parameter.
Library
-------
- Added a new module: cProfile, a C profiler with the same interface as the
profile module. cProfile avoids some of the drawbacks of the hotshot
profiler and provides a bit more information than the other two profilers.
Based on "lsprof" (patch #1212837).
- Bug #1266283: The new function "lexists" is now in os.path.__all__.
- Bug #981530: Fix UnboundLocalError in shutil.rmtree(). This affects
the documented behavior: the function passed to the onerror()
handler can now also be os.listdir.
- Bug #754449: threading.Thread objects no longer mask exceptions raised during
interpreter shutdown with another exception from attempting to handle the
original exception.
- Added decimal.py per PEP 327.
- Bug #981299: rsync is now a recognized protocol in urlparse that uses a
"netloc" portion of a URL.
- Bug #919012: shutil.move() will not try to move a directory into itself.
Thanks Johannes Gijsbers.
- Bug #934282: pydoc.stripid() is now case-insensitive. Thanks Robin Becker.
- Bug #823209: cmath.log() now takes an optional base argument so that its
API matches math.log().
- Bug #957381: distutils bdist_rpm no longer fails on recent RPM versions
that generate a -debuginfo.rpm
- os.path.devnull has been added for all supported platforms.
- Fixed #877165: distutils now picks the right C++ compiler command
on cygwin and mingw32.
- urllib.urlopen().readline() now handles HTTP/0.9 correctly.
- refactored site.py into functions. Also wrote regression tests for the
module.
- The distutils install command now supports the --home option and
installation scheme for all platforms.
- asyncore.loop now has a repeat count parameter that defaults to
looping forever.
- The distutils sdist command now ignores all .svn directories, in
addition to CVS and RCS directories. .svn directories hold
administrative files for the Subversion source control system.
- Added a new module: cookielib. Automatic cookie handling for HTTP
clients. Also, support for cookielib has been added to urllib2, so
urllib2.urlopen() can transparently handle cookies.
- stringprep.py now uses built-in set() instead of sets.Set().
- Bug #876278: Unbounded recursion in modulefinder
- Bug #780300: Swap public and system ID in LexicalHandler.startDTD.
Applications relying on the wrong order need to be corrected.
- Bug #926075: Fixed a bug that returns a wrong pattern object
for a string or unicode object in sre.compile() when a different
type pattern with the same value exists.
- Added countcallers arg to trace.Trace class (--trackcalls command line arg
when run from the command prompt).
- Fixed a caching bug in platform.platform() where the argument of 'terse' was
not taken into consideration when caching value.
- Added two new command-line arguments for profile (output file and
default sort).
- Added global runctx function to profile module
- Add hlist missing entryconfigure and entrycget methods.
- The ptcp154 codec was added for Kazakh character set support.
- Support non-anonymous ftp URLs in urllib2.
- The encodings package will now apply codec name aliases
first before starting to try the import of the codec module.
This simplifies overriding built-in codecs with external
packages, e.g. the included CJK codecs with the JapaneseCodecs
package, by adjusting the aliases dictionary in encodings.aliases
accordingly.
- base64 now supports RFC 3548 Base16, Base32, and Base64 encoding and
decoding standards.
- urllib2 now supports processors. A processor is a handler that
implements an xxx_request or xxx_response method. These methods are
called for all requests.
- distutils compilers now compile source files in the same order as
they are passed to the compiler.
- pprint.pprint() and pprint.pformat() now have additional parameters
indent, width and depth.
- Patch #750542: pprint now will pretty print subclasses of list, tuple
and dict too, as long as they don't overwrite __repr__().
- Bug #848614: distutils' msvccompiler fails to find the MSVC6
compiler because of incomplete registry entries.
- httplib.HTTP.putrequest now offers to omit the implicit Accept-Encoding.
- Patch #841977: modulefinder didn't find extension modules in packages
- imaplib.IMAP4.thread was added.
- Plugged a minor hole in tempfile.mktemp() due to the use of
os.path.exists(), switched to using os.lstat() directly if possible.
- bisect.py and heapq.py now have underlying C implementations
for better performance.
- heapq.py has two new functions, nsmallest() and nlargest().
- traceback.format_exc has been added (similar to print_exc but it returns
a string).
- xmlrpclib.MultiCall has been added.
- poplib.POP3_SSL has been added.
- tmpfile.mkstemp now returns an absolute path even if dir is relative.
- urlparse is RFC 2396 compliant.
- The fieldnames argument to the csv module's DictReader constructor is now
optional. If omitted, the first row of the file will be used as the
list of fieldnames.
- encodings.bz2_codec was added for access to bz2 compression
using "a long string".encode('bz2')
- Various improvements to unittest.py, realigned with PyUnit CVS.
- dircache now passes exceptions to the caller, instead of returning
empty lists.
- The bsddb module and dbhash module now support the iterator and
mapping protocols which make them more substitutable for dictionaries
and shelves.
- The csv module's DictReader and DictWriter classes now accept keyword
arguments. This was an omission in the initial implementation.
- The email package handles some RFC 2231 parameters with missing
CHARSET fields better. It also includes a patch to parameter
parsing when semicolons appear inside quotes.
- sets.py now runs under Py2.2. In addition, the argument restrictions
for most set methods (but not the operators) have been relaxed to
allow any iterable.
- _strptime.py now has a behind-the-scenes caching mechanism for the most
recent TimeRE instance used along with the last five unique directive
patterns. The overall module was also made more thread-safe.
- random.cunifvariate() and random.stdgamma() were deprecated in Py2.3
and removed in Py2.4.
- Bug #823328: urllib2.py's HTTP Digest Auth support works again.
- Patch #873597: CJK codecs are imported into rank of default codecs.
Tools/Demos
-----------
- A hotshotmain script was added to the Tools/scripts directory that
makes it easy to run a script under control of the hotshot profiler.
- The db2pickle and pickle2db scripts can now dump/load gdbm files.
- The file order on the command line of the pickle2db script was reversed.
It is now [ picklefile ] dbfile. This provides better symmetry with
db2pickle. The file arguments to both scripts are now source followed by
destination in situations where both files are given.
- The pydoc script will display a link to the module documentation for
modules determined to be part of the core distribution. The documentation
base directory defaults to http://www.python.org/doc/current/lib/ but can
be changed by setting the PYTHONDOCS environment variable.
- texcheck.py now detects double word errors.
- md5sum.py mistakenly opened input files in text mode by default, a
silent and dangerous change from previous releases. It once again
opens input files in binary mode by default. The -t and -b flags
remain for compatibility with the 2.3 release, but -b is the default
now.
- py-electric-colon now works when pending-delete/delete-selection mode is
in effect
- py-help-at-point is no longer bound to the F1 key - it's still bound to
C-c C-h
- Pynche was fixed to not crash when there is no ~/.pynche file and no
-d option was given.
Build
-----
- Bug #978645: Modules/getpath.c now builds properly in --disable-framework
build under OS X.
- Profiling using gprof is now available if Python is configured with
--enable-profiling.
- Profiling the VM using the Pentium TSC is now possible if Python
is configured --with-tsc.
- In order to find libraries, setup.py now also looks in /lib64, for use
on AMD64.
- Bug #934635: Fixed a bug where the configure script couldn't detect
getaddrinfo() properly if the KAME stack had SCTP support.
- Support for missing ANSI C header files (limits.h, stddef.h, etc) was
removed.
- Systems requiring the D4, D6 or D7 variants of pthreads are no longer
supported (see PEP 11).
- Universal newline support can no longer be disabled (see PEP 11).
- Support for DGUX, SunOS 4, IRIX 4 and Minix was removed (see PEP 11).
- Support for systems requiring --with-dl-dld or --with-sgi-dl was removed
(see PEP 11).
- Tests for sizeof(char) were removed since ANSI C mandates that
sizeof(char) must be 1.
C API
-----
- Thanks to Anthony Tuininga, the datetime module now supplies a C API
containing type-check macros and constructors. See new docs in the
Python/C API Reference Manual for details.
- Private function _PyTime_DoubleToTimet added, to convert a Python
timestamp (C double) to platform time_t with some out-of-bounds
checking. Declared in new header file timefuncs.h. It would be
good to expose some other internal timemodule.c functions there.
- New public functions PyEval_EvaluateFrame and PyGen_New to expose
generator objects.
- New public functions Py_IncRef() and Py_DecRef(), exposing the
functionality of the Py_XINCREF() and Py_XDECREF macros. Useful for
runtime dynamic embedding of Python. See patch #938302, by Bob
Ippolito.
- Added a new macro, PySequence_Fast_ITEMS, which retrieves a fast sequence's
underlying array of PyObject pointers. Useful for high speed looping.
- Created a new method flag, METH_COEXIST, which causes a method to be loaded
even if already defined by a slot wrapper. This allows a __contains__
method, for example, to co-exist with a defined sq_contains slot. This
is helpful because the PyCFunction can take advantage of optimized calls
whenever METH_O or METH_NOARGS flags are defined.
- Added a new function, PyDict_Contains(d, k) which is like
PySequence_Contains() but is specific to dictionaries and executes
about 10% faster.
- Added three new macros: Py_RETURN_NONE, Py_RETURN_TRUE, and Py_RETURN_FALSE.
Each return the singleton they mention after Py_INCREF()ing them.
- Added a new function, PyTuple_Pack(n, ...) for constructing tuples from a
variable length argument list of Python objects without having to invoke
the more complex machinery of Py_BuildValue(). PyTuple_Pack(3, a, b, c)
is equivalent to Py_BuildValue("(OOO)", a, b, c).
Windows
-------
- The _winreg module could segfault when reading very large registry
values, due to unchecked alloca() calls (SF bug 851056). The fix is
uses either PyMem_Malloc(n) or PyString_FromStringAndSize(NULL, n),
as appropriate, followed by a size check.
- file.truncate() could misbehave if the file was open for update
(modes r+, rb+, w+, wb+), and the most recent file operation before
the truncate() call was an input operation. SF bug 801631.
What's New in Python 2.3 final?
===============================
*Release date: 29-Jul-2003*
IDLE
----
- Bug 778400: IDLE hangs when selecting "Edit with IDLE" from explorer.
This was unique to Windows, and was fixed by adding an -n switch to
the command the Windows installer creates to execute "Edit with IDLE"
context-menu actions.
- IDLE displays a new message upon startup: some "personal firewall"
kinds of programs (for example, ZoneAlarm) open a dialog of their
own when any program opens a socket. IDLE does use sockets, talking
on the computer's internal loopback interface. This connection is not
visible on any external interface and no data is sent to or received
from the Internet. So, if you get such a dialog when opening IDLE,
asking whether to let pythonw.exe talk to address 127.0.0.1, say yes,
and rest assured no communication external to your machine is taking
place. If you don't allow it, IDLE won't be able to start.
What's New in Python 2.3 release candidate 2?
=============================================
*Release date: 24-Jul-2003*
Core and builtins
-----------------
- It is now possible to import from zipfiles containing additional
data bytes before the zip compatible archive. Zipfiles containing a
comment at the end are still unsupported.
Extension modules
-----------------
- A longstanding bug in the parser module's initialization could cause
fatal internal refcount confusion when the module got initialized more
than once. This has been fixed.
- Fixed memory leak in pyexpat; using the parser's ParseFile() method
with open files that aren't instances of the standard file type
caused an instance of the bound .read() method to be leaked on every
call.
- Fixed some leaks in the locale module.
Library
-------
- Lib/encodings/rot_13.py when used as a script, now more properly
uses the first Python interpreter on your path.
- Removed caching of TimeRE (and thus LocaleTime) in _strptime.py to
fix a locale related bug in the test suite. Although another patch
was needed to actually fix the problem, the cache code was not
restored.
IDLE
----
- Calltips patches.
Build
-----
- For MacOSX, added -mno-fused-madd to BASECFLAGS to fix test_coercion
on Panther (OSX 10.3).
C API
-----
Windows
-------
- The tempfile module could do insane imports on Windows if PYTHONCASEOK
was set, making temp file creation impossible. Repaired.
- Add a patch to workaround pthread_sigmask() bugs in Cygwin.
Mac
---
- Various fixes to pimp.
- Scripts runs with pythonw no longer had full window manager access.
- Don't force boot-disk-only install, for reasons unknown it causes
more problems than it solves.
What's New in Python 2.3 release candidate 1?
=============================================
*Release date: 18-Jul-2003*
Core and builtins
-----------------
- The new function sys.getcheckinterval() returns the last value set
by sys.setcheckinterval().
- Several bugs in the symbol table phase of the compiler have been
fixed. Errors could be lost and compilation could fail without
reporting an error. SF patch 763201.
- The interpreter is now more robust about importing the warnings
module. In an executable generated by freeze or similar programs,
earlier versions of 2.3 would fail if the warnings module could
not be found on the file system. Fixes SF bug 771097.
- A warning about assignments to module attributes that shadow
builtins, present in earlier releases of 2.3, has been removed.
- It is not possible to create subclasses of builtin types like str
and tuple that define an itemsize. Earlier releases of Python 2.3
allowed this by mistake, leading to crashes and other problems.
- The thread_id is now initialized to 0 in a non-thread build. SF bug
770247.
- SF bug 762891: "del p[key]" on proxy object no longer raises SystemError.
Extension modules
-----------------
- weakref.proxy() can now handle "del obj[i]" for proxy objects
defining __delitem__. Formerly, it generated a SystemError.
- SSL no longer crashes the interpreter when the remote side disconnects.
- On Unix the mmap module can again be used to map device files.
- time.strptime now exclusively uses the Python implementation
contained within the _strptime module.
- The print slot of weakref proxy objects was removed, because it was
not consistent with the object's repr slot.
- The mmap module only checks file size for regular files, not
character or block devices. SF patch 708374.
- The cPickle Pickler garbage collection support was fixed to traverse
the find_class attribute, if present.
- There are several fixes for the bsddb3 wrapper module.
bsddb3 no longer crashes if an environment is closed before a cursor
(SF bug 763298).
The DB and DBEnv set_get_returns_none function was extended to take
a level instead of a boolean flag. The new level 2 means that in
addition, cursor.set()/.get() methods return None instead of raising
an exception.
A typo was fixed in DBCursor.join_item(), preventing a crash.
Library
-------
- distutils now supports MSVC 7.1
- doctest now examines all docstrings by default. Previously, it would
skip over functions with private names (as indicated by the underscore
naming convention). The old default created too much of a risk that
user tests were being skipped inadvertently. Note, this change could
break code in the unlikely case that someone had intentionally put
failing tests in the docstrings of private functions. The breakage
is easily fixable by specifying the old behavior when calling testmod()
or Tester().
- There were several fixes to the way dumbdbms are closed. It's vital
that a dumbdbm database be closed properly, else the on-disk data
and directory files can be left in mutually inconsistent states.
dumbdbm.py's _Database.__del__() method attempted to close the
database properly, but a shutdown race in _Database._commit() could
prevent this from working, so that a program trusting __del__() to
get the on-disk files in synch could be badly surprised. The race
has been repaired. A sync() method was also added so that shelve
can guarantee data is written to disk.
The close() method can now be called more than once without complaint.
- The classes in threading.py are now new-style classes. That they
weren't before was an oversight.
- The urllib2 digest authentication handlers now define the correct
auth_header. The earlier versions would fail at runtime.
- SF bug 763023: fix uncaught ZeroDivisionError in difflib ratio methods
when there are no lines.
- SF bug 763637: fix exception in Tkinter with after_cancel
which could occur with Tk 8.4
- SF bug 770601: CGIHTTPServer.py now passes the entire environment
to child processes.
- SF bug 765238: add filter to fnmatch's __all__.
- SF bug 748201: make time.strptime() error messages more helpful.
- SF patch 764470: Do not dump the args attribute of a Fault object in
xmlrpclib.
- SF patch 549151: urllib and urllib2 now redirect POSTs on 301
responses.
- SF patch 766650: The whichdb module was fixed to recognize dbm files
generated by gdbm on OS/2 EMX.
- SF bugs 763047 and 763052: fixes bug of timezone value being left as
-1 when ``time.tzname[0] == time.tzname[1] and not time.daylight``
is true when it should only when time.daylight is true.
- SF bug 764548: re now allows subclasses of str and unicode to be
used as patterns.
- SF bug 763637: In Tkinter, change after_cancel() to handle tuples
of varying sizes. Tk 8.4 returns a different number of values
than Tk 8.3.
- SF bug 763023: difflib.ratio() did not catch zero division.
- The Queue module now has an __all__ attribute.
Tools/Demos
-----------
- See Lib/idlelib/NEWS.txt for IDLE news.
- SF bug 753592: webchecker/wsgui now handles user supplied directories.
- The trace.py script has been removed. It is now in the standard library.
Build
-----
- Python now compiles with -fno-strict-aliasing if possible (SF bug 766696).
- The socket module compiles on IRIX 6.5.10.
- An irix64 system is treated the same way as an irix6 system (SF
patch 764560).
- Several definitions were missing on FreeBSD 5.x unless the
__BSD_VISIBLE symbol was defined. configure now defines it as
needed.
C API
-----
- Unicode objects now support mbcs as a built-in encoding, so the C
API can use it without deferring to the encodings package.
Windows
-------
- The Windows implementation of PyThread_start_new_thread() never
checked error returns from Windows functions correctly. As a result,
it could claim to start a new thread even when the Microsoft
_beginthread() function failed (due to "too many threads" -- this is
on the order of thousands when it happens). In these cases, the
Python exception ::
thread.error: can't start new thread
is raised now.
- SF bug 766669: Prevent a GPF on interpreter exit when sockets are in
use. The interpreter now calls WSACleanup() from Py_Finalize()
instead of from DLL teardown.
Mac
---
- Bundlebuilder now inherits default values in the right way. It was
previously possible for app bundles to get a type of "BNDL" instead
of "APPL." Other improvements include, a --build-id option to
specify the CFBundleIdentifier and using the --python option to set
the executable in the bundle.
- Fixed two bugs in MacOSX framework handling.
- pythonw did not allow user interaction in 2.3rc1, this has been fixed.
- Python is now compiled with -mno-fused-madd, making all tests pass
on Panther.
What's New in Python 2.3 beta 2?
================================
*Release date: 29-Jun-2003*
Core and builtins
-----------------
- A program can now set the environment variable PYTHONINSPECT to some
string value in Python, and cause the interpreter to enter the
interactive prompt at program exit, as if Python had been invoked
with the -i option.
- list.index() now accepts optional start and stop arguments. Similar
changes were made to UserList.index(). SF feature request 754014.
- SF patch 751998 fixes an unwanted side effect of the previous fix
for SF bug 742860 (the next item).
- SF bug 742860: "WeakKeyDictionary __delitem__ uses iterkeys". This
wasn't threadsafe, was very inefficient (expected time O(len(dict))
instead of O(1)), and could raise a spurious RuntimeError if another
thread mutated the dict during __delitem__, or if a comparison function
mutated it. It also neglected to raise KeyError when the key wasn't
present; didn't raise TypeError when the key wasn't of a weakly
referencable type; and broke various more-or-less obscure dict
invariants by using a sequence of equality comparisons over the whole
set of dict keys instead of computing the key's hash code to narrow
the search to those keys with the same hash code. All of these are
considered to be bugs. A new implementation of __delitem__ repairs all
that, but note that fixing these bugs may change visible behavior in
code relying (whether intentionally or accidentally) on old behavior.
- SF bug 734869: Fixed a compiler bug that caused a fatal error when
compiling a list comprehension that contained another list comprehension
embedded in a lambda expression.
- SF bug 705231: builtin pow() no longer lets the platform C pow()
raise -1.0 to integer powers, because (at least) glibc gets it wrong
in some cases. The result should be -1.0 if the power is odd and 1.0
if the power is even, and any float with a sufficiently large exponent
is (mathematically) an exact even integer.
- SF bug 759227: A new-style class that implements __nonzero__() must
return a bool or int (but not an int subclass) from that method. This
matches the restriction on classic classes.
- The encoding attribute has been added for file objects, and set to
the terminal encoding on Unix and Windows.
- The softspace attribute of file objects became read-only by oversight.
It's writable again.
- Reverted a 2.3 beta 1 change to iterators for subclasses of list and
tuple. By default, the iterators now access data elements directly
instead of going through __getitem__. If __getitem__ access is
preferred, then __iter__ can be overridden.
- SF bug 735247: The staticmethod and super types participate in
garbage collection. Before this change, it was possible for leaks to
occur in functions with non-global free variables that used these types.
Extension modules
-----------------
- the socket module has a new exception, socket.timeout, to allow
timeouts to be handled separately from other socket errors.
- SF bug 751276: cPickle has fixed to propagate exceptions raised in
user code. In earlier versions, cPickle caught and ignored any
exception when it performed operations that it expected to raise
specific exceptions like AttributeError.
- cPickle Pickler and Unpickler objects now participate in garbage
collection.
- mimetools.choose_boundary() could return duplicate strings at times,
especially likely on Windows. The strings returned are now guaranteed
unique within a single program run.
- thread.interrupt_main() raises KeyboardInterrupt in the main thread.
dummy_thread has also been modified to try to simulate the behavior.
- array.array.insert() now treats negative indices as being relative
to the end of the array, just like list.insert() does. (SF bug #739313)
- The datetime module classes datetime, time, and timedelta are now
properly subclassable.
- _tkinter.{get|set}busywaitinterval was added.
- itertools.islice() now accepts stop=None as documented.
Fixes SF bug #730685.
- the bsddb185 module is built in one restricted instance -
/usr/include/db.h exists and defines HASHVERSION to be 2. This is true
for many BSD-derived systems.
Library
-------
- Some happy doctest extensions from Jim Fulton have been added to
doctest.py. These are already being used in Zope3. The two
primary ones:
doctest.debug(module, name) extracts the doctests from the named object
in the given module, puts them in a temp file, and starts pdb running
on that file. This is great when a doctest fails.
doctest.DocTestSuite(module=None) returns a synthesized unittest
TestSuite instance, to be run by the unittest framework, which
runs all the doctests in the module. This allows writing tests in
doctest style (which can be clearer and shorter than writing tests
in unittest style), without losing unittest's powerful testing
framework features (which doctest lacks).
- For compatibility with doctests created before 2.3, if an expected
output block consists solely of "1" and the actual output block
consists solely of "True", it's accepted as a match; similarly
for "0" and "False". This is quite un-doctest-like, but is practical.
The behavior can be disabled by passing the new doctest module
constant DONT_ACCEPT_TRUE_FOR_1 to the new optionflags optional
argument.
- ZipFile.testzip() now only traps BadZipfile exceptions. Previously,
a bare except caught to much and reported all errors as a problem
in the archive.
- The logging module now has a new function, makeLogRecord() making
LogHandler easier to interact with DatagramHandler and SocketHandler.
- The cgitb module has been extended to support plain text display (SF patch
569574).
- A brand new version of IDLE (from the IDLEfork project at
SourceForge) is now included as Lib/idlelib. The old Tools/idle is
no more.
- Added a new module: trace (documentation missing). This module used
to be distributed in Tools/scripts. It uses sys.settrace() to trace
code execution -- either function calls or individual lines. It can
generate tracing output during execution or a post-mortem report of
code coverage.
- The threading module has new functions settrace() and setprofile()
that cooperate with the functions of the same name in the sys
module. A function registered with the threading module will
be used for all threads it creates. The new trace module uses this
to provide tracing for code running in threads.
- copy.py: applied SF patch 707900, fixing bug 702858, by Steven
Taschuk. Copying a new-style class that had a reference to itself
didn't work. (The same thing worked fine for old-style classes.)
Builtin functions are now treated as atomic, fixing bug #746304.
- difflib.py has two new functions: context_diff() and unified_diff().
- More fixes to urllib (SF 549151): (a) When redirecting, always use
GET. This is common practice and more-or-less sanctioned by the
HTTP standard. (b) Add a handler for 307 redirection, which becomes
an error for POST, but a regular redirect for GET and HEAD
- Added optional 'onerror' argument to os.walk(), to control error
handling.
- inspect.is{method|data}descriptor was added, to allow pydoc display
__doc__ of data descriptors.
- Fixed socket speed loss caused by use of the _socketobject wrapper class
in socket.py.
- timeit.py now checks the current directory for imports.
- urllib2.py now knows how to order proxy classes, so the user doesn't
have to insert it in front of other classes, nor do dirty tricks like
inserting a "dummy" HTTPHandler after a ProxyHandler when building an
opener with proxy support.
- Iterators have been added for dbm keys.
- random.Random objects can now be pickled.
Tools/Demos
-----------
- pydoc now offers help on keywords and topics.
- Tools/idle is gone; long live Lib/idlelib.
- diff.py prints file diffs in context, unified, or ndiff formats,
providing a command line interface to difflib.py.
- texcheck.py is a new script for making a rough validation of Python LaTeX
files.
Build
-----
- Setting DESTDIR during 'make install' now allows specifying a
different root directory.
C API
-----
- PyType_Ready(): If a type declares that it participates in gc
(Py_TPFLAGS_HAVE_GC), and its base class does not, and its base class's
tp_free slot is the default _PyObject_Del, and type does not define
a tp_free slot itself, _PyObject_GC_Del is assigned to type->tp_free.
Previously _PyObject_Del was inherited, which could at best lead to a
segfault. In addition, if even after this magic the type's tp_free
slot is _PyObject_Del or NULL, and the type is a base type
(Py_TPFLAGS_BASETYPE), TypeError is raised: since the type is a base
type, its dealloc function must call type->tp_free, and since the type
is gc'able, tp_free must not be NULL or _PyObject_Del.
- PyThreadState_SetAsyncExc(): A new API (deliberately accessible only
from C) to interrupt a thread by sending it an exception. It is
intentional that you have to write your own C extension to call it
from Python.
New platforms
-------------
None this time.
Tests
-----
- test_imp rewritten so that it doesn't raise RuntimeError if run as a
side effect of being imported ("import test.autotest").
Windows
-------
- The Windows installer ships with Tcl/Tk 8.4.3 (upgraded from 8.4.1).
- The installer always suggested that Python be installed on the C:
drive, due to a hardcoded "C:" generated by the Wise installation
wizard. People with machines where C: is not the system drive
usually want Python installed on whichever drive is their system drive
instead. We removed the hardcoded "C:", and two testers on machines
where C: is not the system drive report that the installer now
suggests their system drive. Note that you can always select the
directory you want in the "Select Destination Directory" dialog --
that's what it's for.
Mac
---
- There's a new module called "autoGIL", which offers a mechanism to
automatically release the Global Interpreter Lock when an event loop
goes to sleep, allowing other threads to run. It's currently only
supported on OSX, in the Mach-O version.
- The OSA modules now allow direct access to properties of the
toplevel application class (in AppleScript terminology).
- The Package Manager can now update itself.
SourceForge Bugs and Patches Applied
------------------------------------
430160, 471893, 501716, 542562, 549151, 569574, 595837, 596434,
598163, 604210, 604716, 610332, 612627, 614770, 620190, 621891,
622042, 639139, 640236, 644345, 649742, 649742, 658233, 660022,
661318, 661676, 662807, 662923, 666219, 672855, 678325, 682347,
683486, 684981, 685773, 686254, 692776, 692959, 693094, 696777,
697989, 700827, 703666, 708495, 708604, 708901, 710733, 711902,
713722, 715782, 718286, 719359, 719367, 723136, 723831, 723962,
724588, 724767, 724767, 725942, 726150, 726446, 726869, 727051,
727719, 727719, 727805, 728277, 728563, 728656, 729096, 729103,
729293, 729297, 729300, 729317, 729395, 729622, 729817, 730170,
730296, 730594, 730685, 730826, 730963, 731209, 731403, 731504,
731514, 731626, 731635, 731643, 731644, 731644, 731689, 732124,
732143, 732234, 732284, 732284, 732479, 732761, 732783, 732951,
733667, 733781, 734118, 734231, 734869, 735051, 735293, 735527,
735613, 735694, 736962, 736962, 737970, 738066, 739313, 740055,
740234, 740301, 741806, 742126, 742741, 742860, 742860, 742911,
744041, 744104, 744238, 744687, 744877, 745055, 745478, 745525,
745620, 746012, 746304, 746366, 746801, 746953, 747348, 747667,
747954, 748846, 748849, 748973, 748975, 749191, 749210, 749759,
749831, 749911, 750008, 750092, 750542, 750595, 751038, 751107,
751276, 751451, 751916, 751941, 751956, 751998, 752671, 753451,
753602, 753617, 753845, 753925, 754014, 754340, 754447, 755031,
755087, 755147, 755245, 755683, 755987, 756032, 756996, 757058,
757229, 757818, 757821, 757822, 758112, 758910, 759227, 759889,
760257, 760703, 760792, 761104, 761337, 761519, 761830, 762455
What's New in Python 2.3 beta 1?
================================
*Release date: 25-Apr-2003*
Core and builtins
-----------------
- New format codes B, H, I, k and K have been implemented for
PyArg_ParseTuple and PyBuild_Value.
- New builtin function sum(seq, start=0) returns the sum of all the
items in iterable object seq, plus start (items are normally numbers,
and cannot be strings).
- bool() called without arguments now returns False rather than
raising an exception. This is consistent with calling the
constructors for the other builtin types -- called without argument
they all return the false value of that type. (SF patch #724135)
- In support of PEP 269 (making the pgen parser generator accessible
from Python), some changes to the pgen code structure were made; a
few files that used to be linked only with pgen are now linked with
Python itself.
- The repr() of a weakref object now shows the __name__ attribute of
the referenced object, if it has one.
- super() no longer ignores data descriptors, except __class__. See
the thread started at
http://mail.python.org/pipermail/python-dev/2003-April/034338.html
- list.insert(i, x) now interprets negative i as it would be
interpreted by slicing, so negative values count from the end of the
list. This was the only place where such an interpretation was not
placed on a list index.
- range() now works even if the arguments are longs with magnitude
larger than sys.maxint, as long as the total length of the sequence
fits. E.g., range(2**100, 2**101, 2**100) is the following list:
[1267650600228229401496703205376L]. (SF patch #707427.)
- Some horridly obscure problems were fixed involving interaction
between garbage collection and old-style classes with "ambitious"
getattr hooks. If an old-style instance didn't have a __del__ method,
but did have a __getattr__ hook, and the instance became reachable
only from an unreachable cycle, and the hook resurrected or deleted
unreachable objects when asked to resolve "__del__", anything up to
a segfault could happen. That's been repaired.
- dict.pop now takes an optional argument specifying a default
value to return if the key is not in the dict. If a default is not
given and the key is not found, a KeyError will still be raised.
Parallel changes were made to UserDict.UserDict and UserDict.DictMixin.
[SF patch #693753] (contributed by Michael Stone.)
- sys.getfilesystemencoding() was added to expose
Py_FileSystemDefaultEncoding.
- New function sys.exc_clear() clears the current exception. This is
rarely needed, but can sometimes be useful to release objects
referenced by the traceback held in sys.exc_info()[2]. (SF patch
#693195.)
- On 64-bit systems, a dictionary could contain duplicate long/int keys
if the key value was larger than 2**32. See SF bug #689659.
- Fixed SF bug #663074. The codec system was using global static
variables to store internal data. As a result, any attempts to use the
unicode system with multiple active interpreters, or successive
interpreter executions, would fail.
- "%c" % u"a" now returns a unicode string instead of raising a
TypeError. u"%c" % 0xffffffff now raises a OverflowError instead
of a ValueError to be consistent with "%c" % 256. See SF patch #710127.
Extension modules
-----------------
- The socket module now provides the functions inet_pton and inet_ntop
for converting between string and packed representation of IP
addresses. There is also a new module variable, has_ipv6, which is
True iff the current Python has IPv6 support. See SF patch #658327.
- Tkinter wrappers around Tcl variables now pass objects directly
to Tcl, instead of first converting them to strings.
- The .*? pattern in the re module is now special-cased to avoid the
recursion limit. (SF patch #720991 -- many thanks to Gary Herron
and Greg Chapman.)
- New function sys.call_tracing() allows pdb to debug code
recursively.
- New function gc.get_referents(obj) returns a list of objects
directly referenced by obj. In effect, it exposes what the object's
tp_traverse slot does, and can be helpful when debugging memory
leaks.
- The iconv module has been removed from this release.
- The platform-independent routines for packing floats in IEEE formats
(struct.pack's <f, >f, <d, and >d codes; pickle and cPickle's protocol 1
pickling of floats) ignored that rounding can cause a carry to
propagate. The worst consequence was that, in rare cases, <f and >f
could produce strings that, when unpacked again, were a factor of 2
away from the original float. This has been fixed. See SF bug
#705836.
- New function time.tzset() provides access to the C library tzset()
function, if supported. (SF patch #675422.)
- Using createfilehandler, deletefilehandler, createtimerhandler functions
on Tkinter.tkinter (_tkinter module) no longer crashes the interpreter.
See SF bug #692416.
- Modified the fcntl.ioctl() function to allow modification of a passed
mutable buffer (for details see the reference documentation).
- Made user requested changes to the itertools module.
Subsumed the times() function into repeat().
Added chain() and cycle().
- The rotor module is now deprecated; the encryption algorithm it uses
is not believed to be secure, and including crypto code with Python
has implications for exporting and importing it in various countries.
- The socket module now always uses the _socketobject wrapper class, even on
platforms which have dup(2). The makefile() method is built directly
on top of the socket without duplicating the file descriptor, allowing
timeouts to work properly.
Library
-------
- New generator function os.walk() is an easy-to-use alternative to
os.path.walk(). See os module docs for details. os.path.walk()
isn't deprecated at this time, but may become deprecated in a
future release.
- Added new module "platform" which provides a wide range of tools
for querying platform dependent features.
- netrc now allows ASCII punctuation characters in passwords.
- shelve now supports the optional writeback argument, and exposes
pickle protocol versions.
- Several methods of nntplib.NNTP have grown an optional file argument
which specifies a file where to divert the command's output
(already supported by the body() method). (SF patch #720468)
- The self-documenting XML server library DocXMLRPCServer was added.
- Support for internationalized domain names has been added through
the 'idna' and 'punycode' encodings, the 'stringprep' module, the
'mkstringprep' tool, and enhancements to the socket and httplib
modules.
- htmlentitydefs has two new dictionaries: name2codepoint maps
HTML entity names to Unicode codepoints (as integers).
codepoint2name is the reverse mapping. See SF patch #722017.
- pdb has a new command, "debug", which lets you step through
arbitrary code from the debugger's (pdb) prompt.
- unittest.failUnlessEqual and its equivalent unittest.assertEqual now
return 'not a == b' rather than 'a != b'. This gives the desired
result for classes that define __eq__ without defining __ne__.
- sgmllib now supports SGML marked sections, in particular the
MS Office extensions.
- The urllib module now offers support for the iterator protocol.
SF patch 698520 contributed by Brett Cannon.
- New module timeit provides a simple framework for timing the
execution speed of expressions and statements.
- sets.Set objects now support mixed-type __eq__ and __ne__, instead
of raising TypeError. If x is a Set object and y is a non-Set object,
x == y is False, and x != y is True. This is akin to the change made
for mixed-type comparisons of datetime objects in 2.3a2; more info
about the rationale is in the NEWS entry for that. See also SF bug
report <http://www.python.org/sf/693121>.
- On Unix platforms, if os.listdir() is called with a Unicode argument,
it now returns Unicode strings. (This behavior was added earlier
to the Windows NT/2k/XP version of os.listdir().)
- Distutils: both 'py_modules' and 'packages' keywords can now be specified
in core.setup(). Previously you could supply one or the other, but
not both of them. (SF patch #695090 from Bernhard Herzog)
- New csv package makes it easy to read/write CSV files.
- Module shlex has been extended to allow posix-like shell parsings,
including a split() function for easy spliting of quoted strings and
commands. An iterator interface was also implemented.
Tools/Demos
-----------
- New script combinerefs.py helps analyze new PYTHONDUMPREFS output.
See the module docstring for details.
Build
-----
- Fix problem building on OSF1 because the compiler only accepted
preprocessor directives that start in column 1. (SF bug #691793.)
C API
-----
- Added PyGC_Collect(), equivalent to calling gc.collect().
- PyThreadState_GetDict() was changed not to raise an exception or
issue a fatal error when no current thread state is available. This
makes it possible to print dictionaries when no thread is active.
- LONG_LONG was renamed to PY_LONG_LONG. Extensions that use this and
need compatibility with previous versions can use this:
#ifndef PY_LONG_LONG
#define PY_LONG_LONG LONG_LONG
#endif
- Added PyObject_SelfIter() to fill the tp_iter slot for the
typical case where the method returns its self argument.
- The extended type structure used for heap types (new-style
classes defined by Python code using a class statement) is now
exported from object.h as PyHeapTypeObject. (SF patch #696193.)
New platforms
-------------
None this time.
Tests
-----
- test_timeout now requires -u network to be passed to regrtest to run.
See SF bug #692988.
Windows
-------
- os.fsync() now exists on Windows, and calls the Microsoft _commit()
function.
- New function winsound.MessageBeep() wraps the Win32 API
MessageBeep().
Mac
---
- os.listdir() now returns Unicode strings on MacOS X when called with
a Unicode argument. See the general news item under "Library".
- A new method MacOS.WMAvailable() returns true if it is safe to access
the window manager, false otherwise.
- EasyDialogs dialogs are now movable-modal, and if the application is
currently in the background they will ask to be moved to the foreground
before displaying.
- OSA Scripting support has improved a lot, and gensuitemodule.py can now
be used by mere mortals. The documentation is now also more or less
complete.
- The IDE (in a framework build) now includes introductory documentation
in Apple Help Viewer format.
What's New in Python 2.3 alpha 2?
=================================
*Release date: 19-Feb-2003*
Core and builtins
-----------------
- Negative positions returned from PEP 293 error callbacks are now
treated as being relative to the end of the input string. Positions
that are out of bounds raise an IndexError.
- sys.path[0] (the directory from which the script is loaded) is now
turned into an absolute pathname, unless it is the empty string.
(SF patch #664376.)
- Finally fixed the bug in compile() and exec where a string ending
with an indented code block but no newline would raise SyntaxError.
This would have been a four-line change in parsetok.c... Except
codeop.py depends on this behavior, so a compilation flag had to be
invented that causes the tokenizer to revert to the old behavior;
this required extra changes to 2 .h files, 2 .c files, and 2 .py
files. (Fixes SF bug #501622.)
- If a new-style class defines neither __new__ nor __init__, its
constructor would ignore all arguments. This is changed now: the
constructor refuses arguments in this case. This might break code
that worked under Python 2.2. The simplest fix is to add a no-op
__init__: ``def __init__(self, *args, **kw): pass``.
- Through a bytecode optimizer bug (and I bet you didn't even know
Python *had* a bytecode optimizer :-), "unsigned" hex/oct constants
with a leading minus sign would come out with the wrong sign.
("Unsigned" hex/oct constants are those with a face value in the
range sys.maxint+1 through sys.maxint*2+1, inclusive; these have
always been interpreted as negative numbers through sign folding.)
E.g. 0xffffffff is -1, and -(0xffffffff) is 1, but -0xffffffff would
come out as -4294967295. This was the case in Python 2.2 through
2.2.2 and 2.3a1, and in Python 2.4 it will once again have that
value, but according to PEP 237 it really needs to be 1 now. This
will be backported to Python 2.2.3 a well. (SF #660455)
- int(s, base) sometimes sign-folds hex and oct constants; it only
does this when base is 0 and s.strip() starts with a '0'. When the
sign is actually folded, as in int("0xffffffff", 0) on a 32-bit
machine, which returns -1, a FutureWarning is now issued; in Python
2.4, this will return 4294967295L, as do int("+0xffffffff", 0) and
int("0xffffffff", 16) right now. (PEP 347)
- super(X, x): x may now be a proxy for an X instance, i.e.
issubclass(x.__class__, X) but not issubclass(type(x), X).
- isinstance(x, X): if X is a new-style class, this is now equivalent
to issubclass(type(x), X) or issubclass(x.__class__, X). Previously
only type(x) was tested. (For classic classes this was already the
case.)
- compile(), eval() and the exec statement now fully support source code
passed as unicode strings.
- int subclasses can be initialized with longs if the value fits in an int.
See SF bug #683467.
- long(string, base) takes time linear in len(string) when base is a power
of 2 now. It used to take time quadratic in len(string).
- filter returns now Unicode results for Unicode arguments.
- raw_input can now return Unicode objects.
- List objects' sort() method now accepts None as the comparison function.
Passing None is semantically identical to calling sort() with no
arguments.
- Fixed crash when printing a subclass of str and __str__ returned self.
See SF bug #667147.
- Fixed an invalid RuntimeWarning and an undetected error when trying
to convert a long integer into a float which couldn't fit.
See SF bug #676155.
- Function objects now have a __module__ attribute that is bound to
the name of the module in which the function was defined. This
applies for C functions and methods as well as functions and methods
defined in Python. This attribute is used by pickle.whichmodule(),
which changes the behavior of whichmodule slightly. In Python 2.2
whichmodule() returns "__main__" for functions that are not defined
at the top-level of a module (examples: methods, nested functions).
Now whichmodule() will return the proper module name.
Extension modules
-----------------
- operator.isNumberType() now checks that the object has a nb_int or
nb_float slot, rather than simply checking whether it has a non-NULL
tp_as_number pointer.
- The imp module now has ways to acquire and release the "import
lock": imp.acquire_lock() and imp.release_lock(). Note: this is a
reentrant lock, so releasing the lock only truly releases it when
this is the last release_lock() call. You can check with
imp.lock_held(). (SF bug #580952 and patch #683257.)
- Change to cPickle to match pickle.py (see below and PEP 307).
- Fix some bugs in the parser module. SF bug #678518.
- Thanks to Scott David Daniels, a subtle bug in how the zlib
extension implemented flush() was fixed. Scott also rewrote the
zlib test suite using the unittest module. (SF bug #640230 and
patch #678531.)
- Added an itertools module containing high speed, memory efficient
looping constructs inspired by tools from Haskell and SML.
- The SSL module now handles sockets with a timeout set correctly (SF
patch #675750, fixing SF bug #675552).
- os/posixmodule has grown the sysexits.h constants (EX_OK and friends).
- Fixed broken threadstate swap in readline that could cause fatal
errors when a readline hook was being invoked while a background
thread was active. (SF bugs #660476 and #513033.)
- fcntl now exposes the strops.h I_* constants.
- Fix a crash on Solaris that occurred when calling close() on
an mmap'ed file which was already closed. (SF patch #665913)
- Fixed several serious bugs in the zipimport implementation.
- datetime changes:
The date class is now properly subclassable. (SF bug #720908)
The datetime and datetimetz classes have been collapsed into a single
datetime class, and likewise the time and timetz classes into a single
time class. Previously, a datetimetz object with tzinfo=None acted
exactly like a datetime object, and similarly for timetz. This wasn't
enough of a difference to justify distinct classes, and life is simpler
now.
today() and now() now round system timestamps to the closest
microsecond <http://www.python.org/sf/661086>. This repairs an
irritation most likely seen on Windows systems.
In dt.astimezone(tz), if tz.utcoffset(dt) returns a duration,
ValueError is raised if tz.dst(dt) returns None (2.3a1 treated it
as 0 instead, but a tzinfo subclass wishing to participate in
time zone conversion has to take a stand on whether it supports
DST; if you don't care about DST, then code dst() to return 0 minutes,
meaning that DST is never in effect).
The tzinfo methods utcoffset() and dst() must return a timedelta object
(or None) now. In 2.3a1 they could also return an int or long, but that
was an unhelpfully redundant leftover from an earlier version wherein
they couldn't return a timedelta. TOOWTDI.
The example tzinfo class for local time had a bug. It was replaced
by a later example coded by Guido.
datetime.astimezone(tz) no longer raises an exception when the
input datetime has no UTC equivalent in tz. For typical "hybrid" time
zones (a single tzinfo subclass modeling both standard and daylight
time), this case can arise one hour per year, at the hour daylight time
ends. See new docs for details. In short, the new behavior mimics
the local wall clock's behavior of repeating an hour in local time.
dt.astimezone() can no longer be used to convert between naive and aware
datetime objects. If you merely want to attach, or remove, a tzinfo
object, without any conversion of date and time members, use
dt.replace(tzinfo=whatever) instead, where "whatever" is None or a
tzinfo subclass instance.
A new method tzinfo.fromutc(dt) can be overridden in tzinfo subclasses
to give complete control over how a UTC time is to be converted to
a local time. The default astimezone() implementation calls fromutc()
as its last step, so a tzinfo subclass can affect that too by overriding
fromutc(). It's expected that the default fromutc() implementation will
be suitable as-is for "almost all" time zone subclasses, but the
creativity of political time zone fiddling appears unbounded -- fromutc()
allows the highly motivated to emulate any scheme expressible in Python.
datetime.now(): The optional tzinfo argument was undocumented (that's
repaired), and its name was changed to tz ("tzinfo" is overloaded enough
already). With a tz argument, now(tz) used to return the local date
and time, and attach tz to it, without any conversion of date and time
members. This was less than useful. Now now(tz) returns the current
date and time as local time in tz's time zone, akin to ::
tz.fromutc(datetime.utcnow().replace(tzinfo=utc))
where "utc" is an instance of a tzinfo subclass modeling UTC. Without
a tz argument, now() continues to return the current local date and time,
as a naive datetime object.
datetime.fromtimestamp(): Like datetime.now() above, this had less than
useful behavior when the optional tinzo argument was specified. See
also SF bug report <http://www.python.org/sf/660872>.
date and datetime comparison: In order to prevent comparison from
falling back to the default compare-object-addresses strategy, these
raised TypeError whenever they didn't understand the other object type.
They still do, except when the other object has a "timetuple" attribute,
in which case they return NotImplemented now. This gives other
datetime objects (e.g., mxDateTime) a chance to intercept the
comparison.
date, time, datetime and timedelta comparison: When the exception
for mixed-type comparisons in the last paragraph doesn't apply, if
the comparison is == then False is returned, and if the comparison is
!= then True is returned. Because dict lookup and the "in" operator
only invoke __eq__, this allows, for example, ::
if some_datetime in some_sequence:
and ::
some_dict[some_timedelta] = whatever
to work as expected, without raising TypeError just because the
sequence is heterogeneous, or the dict has mixed-type keys. [This
seems like a good idea to implement for all mixed-type comparisons
that don't want to allow falling back to address comparison.]
The constructors building a datetime from a timestamp could raise
ValueError if the platform C localtime()/gmtime() inserted "leap
seconds". Leap seconds are ignored now. On such platforms, it's
possible to have timestamps that differ by a second, yet where
datetimes constructed from them are equal.
The pickle format of date, time and datetime objects has changed
completely. The undocumented pickler and unpickler functions no
longer exist. The undocumented __setstate__() and __getstate__()
methods no longer exist either.
Library
-------
- The logging module was updated slightly; the WARN level was renamed
to WARNING, and the matching function/method warn() to warning().
- The pickle and cPickle modules were updated with a new pickling
protocol (documented by pickletools.py, see below) and several
extensions to the pickle customization API (__reduce__, __setstate__
etc.). The copy module now uses more of the pickle customization
API to copy objects that don't implement __copy__ or __deepcopy__.
See PEP 307 for details.
- The distutils "register" command now uses http://www.python.org/pypi
as the default repository. (See PEP 301.)
- the platform dependent path related variables sep, altsep, extsep,
pathsep, curdir, pardir and defpath are now defined in the platform
dependent path modules (e.g. ntpath.py) rather than os.py, so these
variables are now available via os.path. They continue to be
available from the os module.
(see <http://www.python.org/sf/680789>).
- array.array was added to the types repr.py knows about (see
<http://www.python.org/sf/680789>).
- The new pickletools.py contains lots of documentation about pickle
internals, and supplies some helpers for working with pickles, such as
a symbolic pickle disassembler.
- Xmlrpclib.py now supports the builtin boolean type.
- py_compile has a new 'doraise' flag and a new PyCompileError
exception.
- SimpleXMLRPCServer now supports CGI through the CGIXMLRPCRequestHandler
class.
- The sets module now raises TypeError in __cmp__, to clarify that
sets are not intended to be three-way-compared; the comparison
operators are overloaded as subset/superset tests.
- Bastion.py and rexec.py are disabled. These modules are not safe in
Python 2.2. or 2.3.
- realpath is now exported when doing ``from poxixpath import *``.
It is also exported for ntpath, macpath, and os2emxpath.
See SF bug #659228.
- New module tarfile from Lars Gustäbel provides a comprehensive interface
to tar archive files with transparent gzip and bzip2 compression.
See SF patch #651082.
- urlparse can now parse imap:// URLs. See SF feature request #618024.
- Tkinter.Canvas.scan_dragto() provides an optional parameter to support
the gain value which is passed to Tk. SF bug# 602259.
- Fix logging.handlers.SysLogHandler protocol when using UNIX domain sockets.
See SF patch #642974.
- The dospath module was deleted. Use the ntpath module when manipulating
DOS paths from other platforms.
Tools/Demos
-----------
- Two new scripts (db2pickle.py and pickle2db.py) were added to the
Tools/scripts directory to facilitate conversion from the old bsddb module
to the new one. While the user-visible API of the new module is
compatible with the old one, it's likely that the version of the
underlying database library has changed. To convert from the old library,
run the db2pickle.py script using the old version of Python to convert it
to a pickle file. After upgrading Python, run the pickle2db.py script
using the new version of Python to reconstitute your database. For
example:
% python2.2 db2pickle.py -h some.db > some.pickle
% python2.3 pickle2db.py -h some.db.new < some.pickle
Run the scripts without any args to get a usage message.
Build
-----
- The audio driver tests (test_ossaudiodev.py and
test_linuxaudiodev.py) are no longer run by default. This is
because they don't always work, depending on your hardware and
software. To run these tests, you must use an invocation like ::
./python Lib/test/regrtest.py -u audio test_ossaudiodev
- On systems which build using the configure script, compiler flags which
used to be lumped together using the OPT flag have been split into two
groups, OPT and BASECFLAGS. OPT is meant to carry just optimization- and
debug-related flags like "-g" and "-O3". BASECFLAGS is meant to carry
compiler flags that are required to get a clean compile. On some
platforms (many Linux flavors in particular) BASECFLAGS will be empty by
default. On others, such as Mac OS X and SCO, it will contain required
flags. This change allows people building Python to override OPT without
fear of clobbering compiler flags which are required to get a clean build.
- On Darwin/Mac OS X platforms, /sw/lib and /sw/include are added to the
relevant search lists in setup.py. This allows users building Python to
take advantage of the many packages available from the fink project
<http://fink.sf.net/>.
- A new Makefile target, scriptsinstall, installs a number of useful scripts
from the Tools/scripts directory.
C API
-----
- PyEval_GetFrame() is now declared to return a ``PyFrameObject *``
instead of a plain ``PyObject *``. (SF patch #686601.)
- PyNumber_Check() now checks that the object has a nb_int or nb_float
slot, rather than simply checking whether it has a non-NULL
tp_as_number pointer.
- A C type that inherits from a base type that defines tp_as_buffer
will now inherit the tp_as_buffer pointer if it doesn't define one.
(SF #681367)
- The PyArg_Parse functions now issue a DeprecationWarning if a float
argument is provided when an integer is specified (this affects the 'b',
'B', 'h', 'H', 'i', and 'l' codes). Future versions of Python will
raise a TypeError.
Tests
-----
- Several tests weren't being run from regrtest.py (test_timeout.py,
test_tarfile.py, test_netrc.py, test_multifile.py,
test_importhooks.py and test_imp.py). Now they are. (Note to
developers: please read Lib/test/README when creating a new test, to
make sure to do it right! All tests need to use either unittest or
pydoc.)
- Added test_posix.py, a test suite for the posix module.
- Added test_hexoct.py, a test suite for hex/oct constant folding.
Windows
-------
- The timeout code for socket connect() didn't work right; this has
now been fixed. test_timeout.py should pass (at least most of the
time).
- distutils' msvccompiler class now passes the preprocessor options to
the resource compiler. See SF patch #669198.
- The bsddb module now ships with Sleepycat's 4.1.25.NC, the latest
release without strong cryptography.
- sys.path[0], if it contains a directory name, is now always an
absolute pathname. (SF patch #664376.)
- The new logging package is now installed by the Windows installer. It
wasn't in 2.3a1 due to oversight.
Mac
---
- There are new dialogs EasyDialogs.AskFileForOpen, AskFileForSave
and AskFolder. The old macfs.StandardGetFile and friends are deprecated.
- Most of the standard library now uses pathnames or FSRefs in preference
of FSSpecs, and use the underlying Carbon.File and Carbon.Folder modules
in stead of macfs. macfs will probably be deprecated in the future.
- Type Carbon.File.FSCatalogInfo and supporting methods have been implemented.
This also makes macfs.FSSpec.SetDates() work again.
- There is a new module pimp, the package install manager for Python, and
accompanying applet PackageManager. These allow you to easily download
and install pretested extension packages either in source or binary
form. Only in MacPython-OSX.
- Applets are now built with bundlebuilder in MacPython-OSX, which should make
them more robust and also provides a path towards BuildApplication. The
downside of this change is that applets can no longer be run from the
Terminal window, this will hopefully be fixed in the 2.3b1.
What's New in Python 2.3 alpha 1?
=================================
*Release date: 31-Dec-2002*
Type/class unification and new-style classes
--------------------------------------------
- One can now assign to __bases__ and __name__ of new-style classes.
- dict() now accepts keyword arguments so that dict(one=1, two=2)
is the equivalent of {"one": 1, "two": 2}. Accordingly,
the existing (but undocumented) 'items' keyword argument has
been eliminated. This means that dict(items=someMapping) now has
a different meaning than before.
- int() now returns a long object if the argument is outside the
integer range, so int("4" * 1000), int(1e200) and int(1L<<1000) will
all return long objects instead of raising an OverflowError.
- Assignment to __class__ is disallowed if either the old or the new
class is a statically allocated type object (such as defined by an
extension module). This prevents anomalies like 2.__class__ = bool.
- New-style object creation and deallocation have been sped up
significantly; they are now faster than classic instance creation
and deallocation.
- The __slots__ variable can now mention "private" names, and the
right thing will happen (e.g. __slots__ = ["__foo"]).
- The built-ins slice() and buffer() are now callable types. The
types classobj (formerly class), code, function, instance, and
instancemethod (formerly instance-method), which have no built-in
names but are accessible through the types module, are now also
callable. The type dict-proxy is renamed to dictproxy.
- Cycles going through the __class__ link of a new-style instance are
now detected by the garbage collector.
- Classes using __slots__ are now properly garbage collected.
[SF bug 519621]
- Tightened the __slots__ rules: a slot name must be a valid Python
identifier.
- The constructor for the module type now requires a name argument and
takes an optional docstring argument. Previously, this constructor
ignored its arguments. As a consequence, deriving a class from a
module (not from the module type) is now illegal; previously this
created an unnamed module, just like invoking the module type did.
[SF bug 563060]
- A new type object, 'basestring', is added. This is a common base type
for 'str' and 'unicode', and can be used instead of
types.StringTypes, e.g. to test whether something is "a string":
isinstance(x, basestring) is True for Unicode and 8-bit strings. This
is an abstract base class and cannot be instantiated directly.
- Changed new-style class instantiation so that when C's __new__
method returns something that's not a C instance, its __init__ is
not called. [SF bug #537450]
- Fixed super() to work correctly with class methods. [SF bug #535444]
- If you try to pickle an instance of a class that has __slots__ but
doesn't define or override __getstate__, a TypeError is now raised.
This is done by adding a bozo __getstate__ to the class that always
raises TypeError. (Before, this would appear to be pickled, but the
state of the slots would be lost.)
Core and builtins
-----------------
- Import from zipfiles is now supported. The name of a zipfile placed
on sys.path causes the import statement to look for importable Python
modules (with .py, pyc and .pyo extensions) and packages inside the
zipfile. The zipfile import follows the specification (though not
the sample implementation) of PEP 273. The semantics of __path__ are
compatible with those that have been implemented in Jython since
Jython 2.1.
- PEP 302 has been accepted. Although it was initially developed to
support zipimport, it offers a new, general import hook mechanism.
Several new variables have been added to the sys module:
sys.meta_path, sys.path_hooks, and sys.path_importer_cache; these
make extending the import statement much more convenient than
overriding the __import__ built-in function. For a description of
these, see PEP 302.
- A frame object's f_lineno attribute can now be written to from a
trace function to change which line will execute next. A command to
exploit this from pdb has been added. [SF patch #643835]
- The _codecs support module for codecs.py was turned into a builtin
module to assure that at least the builtin codecs are available
to the Python parser for source code decoding according to PEP 263.
- issubclass now supports a tuple as the second argument, just like
isinstance does. ``issubclass(X, (A, B))`` is equivalent to
``issubclass(X, A) or issubclass(X, B)``.
- Thanks to Armin Rigo, the last known way to provoke a system crash
by cleverly arranging for a comparison function to mutate a list
during a list.sort() operation has been fixed. The effect of
attempting to mutate a list, or even to inspect its contents or
length, while a sort is in progress, is not defined by the language.
The C implementation of Python 2.3 attempts to detect mutations,
and raise ValueError if one occurs, but there's no guarantee that
all mutations will be caught, or that any will be caught across
releases or implementations.
- Unicode file name processing for Windows (PEP 277) is implemented.
All platforms now have an os.path.supports_unicode_filenames attribute,
which is set to True on Windows NT/2000/XP, and False elsewhere.
- Codec error handling callbacks (PEP 293) are implemented.
Error handling in unicode.encode or str.decode can now be customized.
- A subtle change to the semantics of the built-in function intern():
interned strings are no longer immortal. You must keep a reference
to the return value intern() around to get the benefit.
- Use of 'None' as a variable, argument or attribute name now
issues a SyntaxWarning. In the future, None may become a keyword.
- SET_LINENO is gone. co_lnotab is now consulted to determine when to
call the trace function. C code that accessed f_lineno should call
PyCode_Addr2Line instead (f_lineno is still there, but only kept up
to date when there is a trace function set).
- There's a new warning category, FutureWarning. This is used to warn
about a number of situations where the value or sign of an integer
result will change in Python 2.4 as a result of PEP 237 (integer
unification). The warnings implement stage B0 mentioned in that
PEP. The warnings are about the following situations:
- Octal and hex literals without 'L' prefix in the inclusive range
[0x80000000..0xffffffff]; these are currently negative ints, but
in Python 2.4 they will be positive longs with the same bit
pattern.
- Left shifts on integer values that cause the outcome to lose
bits or have a different sign than the left operand. To be
precise: x<<n where this currently doesn't yield the same value
as long(x)<<n; in Python 2.4, the outcome will be long(x)<<n.
- Conversions from ints to string that show negative values as
unsigned ints in the inclusive range [0x80000000..0xffffffff];
this affects the functions hex() and oct(), and the string
formatting codes %u, %o, %x, and %X. In Python 2.4, these will
show signed values (e.g. hex(-1) currently returns "0xffffffff";
in Python 2.4 it will return "-0x1").
- The bits manipulated under the cover by sys.setcheckinterval() have
been changed. Both the check interval and the ticker used to be
per-thread values. They are now just a pair of global variables.
In addition, the default check interval was boosted from 10 to 100
bytecode instructions. This may have some effect on systems that
relied on the old default value. In particular, in multi-threaded
applications which try to be highly responsive, response time will
increase by some (perhaps imperceptible) amount.
- When multiplying very large integers, a version of the so-called
Karatsuba algorithm is now used. This is most effective if the
inputs have roughly the same size. If they both have about N digits,
Karatsuba multiplication has O(N**1.58) runtime (the exponent is
log_base_2(3)) instead of the previous O(N**2). Measured results may
be better or worse than that, depending on platform quirks. Besides
the O() improvement in raw instruction count, the Karatsuba algorithm
appears to have much better cache behavior on extremely large integers
(starting in the ballpark of a million bits). Note that this is a
simple implementation, and there's no intent here to compete with,
e.g., GMP. It gives a very nice speedup when it applies, but a package
devoted to fast large-integer arithmetic should run circles around it.
- u'%c' will now raise a ValueError in case the argument is an
integer outside the valid range of Unicode code point ordinals.
- The tempfile module has been overhauled for enhanced security. The
mktemp() function is now deprecated; new, safe replacements are
mkstemp() (for files) and mkdtemp() (for directories), and the
higher-level functions NamedTemporaryFile() and TemporaryFile().
Use of some global variables in this module is also deprecated; the
new functions have keyword arguments to provide the same
functionality. All Lib, Tools and Demo modules that used the unsafe
interfaces have been updated to use the safe replacements. Thanks
to Zack Weinberg!
- When x is an object whose class implements __mul__ and __rmul__,
1.0*x would correctly invoke __rmul__, but 1*x would erroneously
invoke __mul__. This was due to the sequence-repeat code in the int
type. This has been fixed now.
- Previously, "str1 in str2" required str1 to be a string of length 1.
This restriction has been relaxed to allow str1 to be a string of
any length. Thus "'el' in 'hello world'" returns True now.
- File objects are now their own iterators. For a file f, iter(f) now
returns f (unless f is closed), and f.next() is similar to
f.readline() when EOF is not reached; however, f.next() uses a
readahead buffer that messes up the file position, so mixing
f.next() and f.readline() (or other methods) doesn't work right.
Calling f.seek() drops the readahead buffer, but other operations
don't. It so happens that this gives a nice additional speed boost
to "for line in file:"; the xreadlines method and corresponding
module are now obsolete. Thanks to Oren Tirosh!
- Encoding declarations (PEP 263, phase 1) have been implemented. A
comment of the form "# -*- coding: <encodingname> -*-" in the first
or second line of a Python source file indicates the encoding.
- list.sort() has a new implementation. While cross-platform results
may vary, and in data-dependent ways, this is much faster on many
kinds of partially ordered lists than the previous implementation,
and reported to be just as fast on randomly ordered lists on
several major platforms. This sort is also stable (if A==B and A
precedes B in the list at the start, A precedes B after the sort too),
although the language definition does not guarantee stability. A
potential drawback is that list.sort() may require temp space of
len(list)*2 bytes (``*4`` on a 64-bit machine). It's therefore possible
for list.sort() to raise MemoryError now, even if a comparison function
does not. See <http://www.python.org/sf/587076> for full details.
- All standard iterators now ensure that, once StopIteration has been
raised, all future calls to next() on the same iterator will also
raise StopIteration. There used to be various counterexamples to
this behavior, which could caused confusion or subtle program
breakage, without any benefits. (Note that this is still an
iterator's responsibility; the iterator framework does not enforce
this.)
- Ctrl+C handling on Windows has been made more consistent with
other platforms. KeyboardInterrupt can now reliably be caught,
and Ctrl+C at an interactive prompt no longer terminates the
process under NT/2k/XP (it never did under Win9x). Ctrl+C will
interrupt time.sleep() in the main thread, and any child processes
created via the popen family (on win2k; we can't make win9x work
reliably) are also interrupted (as generally happens on for Linux/Unix.)
[SF bugs 231273, 439992 and 581232]
- sys.getwindowsversion() has been added on Windows. This
returns a tuple with information about the version of Windows
currently running.
- Slices and repetitions of buffer objects now consistently return
a string. Formerly, strings would be returned most of the time,
but a buffer object would be returned when the repetition count
was one or when the slice range was all inclusive.
- Unicode objects in sys.path are no longer ignored but treated
as directory names.
- Fixed string.startswith and string.endswith builtin methods
so they accept negative indices. [SF bug 493951]
- Fixed a bug with a continue inside a try block and a yield in the
finally clause. [SF bug 567538]
- Most builtin sequences now support "extended slices", i.e. slices
with a third "stride" parameter. For example, "hello world"[::-1]
gives "dlrow olleh".
- A new warning PendingDeprecationWarning was added to provide
direction on features which are in the process of being deprecated.
The warning will not be printed by default. To see the pending
deprecations, use -Walways::PendingDeprecationWarning::
as a command line option or warnings.filterwarnings() in code.
- Deprecated features of xrange objects have been removed as
promised. The start, stop, and step attributes and the tolist()
method no longer exist. xrange repetition and slicing have been
removed.
- New builtin function enumerate(x), from PEP 279. Example:
enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
The argument can be an arbitrary iterable object.
- The assert statement no longer tests __debug__ at runtime. This means
that assert statements cannot be disabled by assigning a false value
to __debug__.
- A method zfill() was added to str and unicode, that fills a numeric
string to the left with zeros. For example,
"+123".zfill(6) -> "+00123".
- Complex numbers supported divmod() and the // and % operators, but
these make no sense. Since this was documented, they're being
deprecated now.
- String and unicode methods lstrip(), rstrip() and strip() now take
an optional argument that specifies the characters to strip. For
example, "Foo!!!?!?!?".rstrip("?!") -> "Foo".
- There's a new dictionary constructor (a class method of the dict
class), dict.fromkeys(iterable, value=None). It constructs a
dictionary with keys taken from the iterable and all values set to a
single value. It can be used for building sets and for removing
duplicates from sequences.
- Added a new dict method pop(key). This removes and returns the
value corresponding to key. [SF patch #539949]
- A new built-in type, bool, has been added, as well as built-in
names for its two values, True and False. Comparisons and sundry
other operations that return a truth value have been changed to
return a bool instead. Read PEP 285 for an explanation of why this
is backward compatible.
- Fixed two bugs reported as SF #535905: under certain conditions,
deallocating a deeply nested structure could cause a segfault in the
garbage collector, due to interaction with the "trashcan" code;
access to the current frame during destruction of a local variable
could access a pointer to freed memory.
- The optional object allocator ("pymalloc") has been enabled by
default. The recommended practice for memory allocation and
deallocation has been streamlined. A header file is included,
Misc/pymemcompat.h, which can be bundled with 3rd party extensions
and lets them use the same API with Python versions from 1.5.2
onwards.
- PyErr_Display will provide file and line information for all exceptions
that have an attribute print_file_and_line, not just SyntaxErrors.
- The UTF-8 codec will now encode and decode Unicode surrogates
correctly and without raising exceptions for unpaired ones.
- Universal newlines (PEP 278) is implemented. Briefly, using 'U'
instead of 'r' when opening a text file for reading changes the line
ending convention so that any of '\r', '\r\n', and '\n' is
recognized (even mixed in one file); all three are converted to
'\n', the standard Python line end character.
- file.xreadlines() now raises a ValueError if the file is closed:
Previously, an xreadlines object was returned which would raise
a ValueError when the xreadlines.next() method was called.
- sys.exit() inadvertently allowed more than one argument.
An exception will now be raised if more than one argument is used.
- Changed evaluation order of dictionary literals to conform to the
general left to right evaluation order rule. Now {f1(): f2()} will
evaluate f1 first.
- Fixed bug #521782: when a file was in non-blocking mode, file.read()
could silently lose data or wrongly throw an unknown error.
- The sq_repeat, sq_inplace_repeat, sq_concat and sq_inplace_concat
slots are now always tried after trying the corresponding nb_* slots.
This fixes a number of minor bugs (see bug #624807).
- Fix problem with dynamic loading on 64-bit AIX (see bug #639945).
Extension modules
-----------------
- Added three operators to the operator module:
operator.pow(a,b) which is equivalent to: a**b.
operator.is_(a,b) which is equivalent to: a is b.
operator.is_not(a,b) which is equivalent to: a is not b.
- posix.openpty now works on all systems that have /dev/ptmx.
- A module zipimport exists to support importing code from zip
archives.
- The new datetime module supplies classes for manipulating dates and
times. The basic design came from the Zope "fishbowl process", and
favors practical commercial applications over calendar esoterica. See
http://www.zope.org/Members/fdrake/DateTimeWiki/FrontPage
- _tkinter now returns Tcl objects, instead of strings. Objects which
have Python equivalents are converted to Python objects, other objects
are wrapped. This can be configured through the wantobjects method,
or Tkinter.wantobjects.
- The PyBSDDB wrapper around the Sleepycat Berkeley DB library has
been added as the package bsddb. The traditional bsddb module is
still available in source code, but not built automatically anymore,
and is now named bsddb185. This supports Berkeley DB versions from
3.0 to 4.1. For help converting your databases from the old module (which
probably used an obsolete version of Berkeley DB) to the new module, see
the db2pickle.py and pickle2db.py scripts described in the Tools/Demos
section above.
- unicodedata was updated to Unicode 3.2. It supports normalization
and names for Hangul syllables and CJK unified ideographs.
- resource.getrlimit() now returns longs instead of ints.
- readline now dynamically adjusts its input/output stream if
sys.stdin/stdout changes.
- The _tkinter module (and hence Tkinter) has dropped support for
Tcl/Tk 8.0 and 8.1. Only Tcl/Tk versions 8.2, 8.3 and 8.4 are
supported.
- cPickle.BadPickleGet is now a class.
- The time stamps in os.stat_result are floating point numbers
after stat_float_times has been called.
- If the size passed to mmap.mmap() is larger than the length of the
file on non-Windows platforms, a ValueError is raised. [SF bug 585792]
- The xreadlines module is slated for obsolescence.
- The strptime function in the time module is now always available (a
Python implementation is used when the C library doesn't define it).
- The 'new' module is no longer an extension, but a Python module that
only exists for backwards compatibility. Its contents are no longer
functions but callable type objects.
- The bsddb.*open functions can now take 'None' as a filename.
This will create a temporary in-memory bsddb that won't be
written to disk.
- posix.getloadavg, posix.lchown, posix.killpg, posix.mknod, and
posix.getpgid have been added where available.
- The locale module now exposes the C library's gettext interface. It
also has a new function getpreferredencoding.
- A security hole ("double free") was found in zlib-1.1.3, a popular
third party compression library used by some Python modules. The
hole was quickly plugged in zlib-1.1.4, and the Windows build of
Python now ships with zlib-1.1.4.
- pwd, grp, and resource return enhanced tuples now, with symbolic
field names.
- array.array is now a type object. A new format character
'u' indicates Py_UNICODE arrays. For those, .tounicode and
.fromunicode methods are available. Arrays now support __iadd__
and __imul__.
- dl now builds on every system that has dlfcn.h. Failure in case
of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open
is called.
- The sys module acquired a new attribute, api_version, which evaluates
to the value of the PYTHON_API_VERSION macro with which the
interpreter was compiled.
- Fixed bug #470582: sre module would return a tuple (None, 'a', 'ab')
when applying the regular expression '^((a)c)?(ab)$' on 'ab'. It now
returns (None, None, 'ab'), as expected. Also fixed handling of
lastindex/lastgroup match attributes in similar cases. For example,
when running the expression r'(a)(b)?b' over 'ab', lastindex must be
1, not 2.
- Fixed bug #581080: sre scanner was not checking the buffer limit
before increasing the current pointer. This was creating an infinite
loop in the search function, once the pointer exceeded the buffer
limit.
- The os.fdopen function now enforces a file mode starting with the
letter 'r', 'w' or 'a', otherwise a ValueError is raised. This fixes
bug #623464.
- The linuxaudiodev module is now deprecated; it is being replaced by
ossaudiodev. The interface has been extended to cover a lot more of
OSS (see www.opensound.com), including most DSP ioctls and the
OSS mixer API. Documentation forthcoming in 2.3a2.
Library
-------
- imaplib.py now supports SSL (Tino Lange and Piers Lauder).
- Freeze's modulefinder.py has been moved to the standard library;
slightly improved so it will issue less false missing submodule
reports (see sf path #643711 for details). Documentation will follow
with Python 2.3a2.
- os.path exposes getctime.
- unittest.py now has two additional methods called assertAlmostEqual()
and failIfAlmostEqual(). They implement an approximate comparison
by rounding the difference between the two arguments and comparing
the result to zero. Approximate comparison is essential for
unit tests of floating point results.
- calendar.py now depends on the new datetime module rather than
the time module. As a result, the range of allowable dates
has been increased.
- pdb has a new 'j(ump)' command to select the next line to be
executed.
- The distutils created windows installers now can run a
postinstallation script.
- doctest.testmod can now be called without argument, which means to
test the current module.
- When canceling a server that implemented threading with a keyboard
interrupt, the server would shut down but not terminate (waiting on
client threads). A new member variable, daemon_threads, was added to
the ThreadingMixIn class in SocketServer.py to make it explicit that
this behavior needs to be controlled.
- A new module, optparse, provides a fancy alternative to getopt for
command line parsing. It is a slightly modified version of Greg
Ward's Optik package.
- UserDict.py now defines a DictMixin class which defines all dictionary
methods for classes that already have a minimum mapping interface.
This greatly simplifies writing classes that need to be substitutable
for dictionaries (such as the shelve module).
- shelve.py now subclasses from UserDict.DictMixin. Now shelve supports
all dictionary methods. This eases the transition to persistent
storage for scripts originally written with dictionaries in mind.
- shelve.open and the various classes in shelve.py now accept an optional
binary flag, which defaults to False. If True, the values stored in the
shelf are binary pickles.
- A new package, logging, implements the logging API defined by PEP
282. The code is written by Vinay Sajip.
- StreamReader, StreamReaderWriter and StreamRecoder in the codecs
modules are iterators now.
- gzip.py now handles files exceeding 2GB. Files over 4GB also work
now (provided the OS supports it, and Python is configured with large
file support), but in that case the underlying gzip file format can
record only the least-significant 32 bits of the file size, so that
some tools working with gzipped files may report an incorrect file
size.
- xml.sax.saxutils.unescape has been added, to replace entity references
with their entity value.
- Queue.Queue.{put,get} now support an optional timeout argument.
- Various features of Tk 8.4 are exposed in Tkinter.py. The multiple
option of tkFileDialog is exposed as function askopenfile{,name}s.
- Various configure methods of Tkinter have been stream-lined, so that
tag_configure, image_configure, window_configure now return a
dictionary when invoked with no argument.
- Importing the readline module now no longer has the side effect of
calling setlocale(LC_CTYPE, ""). The initial "C" locale, or
whatever locale is explicitly set by the user, is preserved. If you
want repr() of 8-bit strings in your preferred encoding to preserve
all printable characters of that encoding, you have to add the
following code to your $PYTHONSTARTUP file or to your application's
main():
import locale
locale.setlocale(locale.LC_CTYPE, "")
- shutil.move was added. shutil.copytree now reports errors as an
exception at the end, instead of printing error messages.
- Encoding name normalization was generalized to not only
replace hyphens with underscores, but also all other non-alphanumeric
characters (with the exception of the dot which is used for Python
package names during lookup). The aliases.py mapping was updated
to the new standard.
- mimetypes has two new functions: guess_all_extensions() which
returns a list of all known extensions for a mime type, and
add_type() which adds one mapping between a mime type and
an extension to the database.
- New module: sets, defines the class Set that implements a mutable
set type using the keys of a dict to represent the set. There's
also a class ImmutableSet which is useful when you need sets of sets
or when you need to use sets as dict keys, and a class BaseSet which
is the base class of the two.
- Added random.sample(population,k) for random sampling without replacement.
Returns a k length list of unique elements chosen from the population.
- random.randrange(-sys.maxint-1, sys.maxint) no longer raises
OverflowError. That is, it now accepts any combination of 'start'
and 'stop' arguments so long as each is in the range of Python's
bounded integers.
- Thanks to Raymond Hettinger, random.random() now uses a new core
generator. The Mersenne Twister algorithm is implemented in C,
threadsafe, faster than the previous generator, has an astronomically
large period (2**19937-1), creates random floats to full 53-bit
precision, and may be the most widely tested random number generator
in existence.
The random.jumpahead(n) method has different semantics for the new
generator. Instead of jumping n steps ahead, it uses n and the
existing state to create a new state. This means that jumpahead()
continues to support multi-threaded code needing generators of
non-overlapping sequences. However, it will break code which relies
on jumpahead moving a specific number of steps forward.
The attributes random.whseed and random.__whseed have no meaning for
the new generator. Code using these attributes should switch to a
new class, random.WichmannHill which is provided for backward
compatibility and to make an alternate generator available.
- New "algorithms" module: heapq, implements a heap queue. Thanks to
Kevin O'Connor for the code and François Pinard for an entertaining
write-up explaining the theory and practical uses of heaps.
- New encoding for the Palm OS character set: palmos.
- binascii.crc32() and the zipfile module had problems on some 64-bit
platforms. These have been fixed. On a platform with 8-byte C longs,
crc32() now returns a signed-extended 4-byte result, so that its value
as a Python int is equal to the value computed a 32-bit platform.
- xml.dom.minidom.toxml and toprettyxml now take an optional encoding
argument.
- Some fixes in the copy module: when an object is copied through its
__reduce__ method, there was no check for a __setstate__ method on
the result [SF patch 565085]; deepcopy should treat instances of
custom metaclasses the same way it treats instances of type 'type'
[SF patch 560794].
- Sockets now support timeout mode. After s.settimeout(T), where T is
a float expressing seconds, subsequent operations raise an exception
if they cannot be completed within T seconds. To disable timeout
mode, use s.settimeout(None). There's also a module function,
socket.setdefaulttimeout(T), which sets the default for all sockets
created henceforth.
- getopt.gnu_getopt was added. This supports GNU-style option
processing, where options can be mixed with non-option arguments.
- Stop using strings for exceptions. String objects used for
exceptions are now classes deriving from Exception. The objects
changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error,
tabnanny.NannyNag, and xdrlib.Error.
- Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE,
BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte
Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and
big endian systems were added to the codecs module. The old names
BOM32_* and BOM64_* were off by a factor of 2.
- Added conversion functions math.degrees() and math.radians().
- math.log() now takes an optional argument: math.log(x[, base]).
- ftplib.retrlines() now tests for callback is None rather than testing
for False. Was causing an error when given a callback object which
was callable but also returned len() as zero. The change may
create new breakage if the caller relied on the undocumented behavior
and called with callback set to [] or some other False value not
identical to None.
- random.gauss() uses a piece of hidden state used by nothing else,
and the .seed() and .whseed() methods failed to reset it. In other
words, setting the seed didn't completely determine the sequence of
results produced by random.gauss(). It does now. Programs repeatedly
mixing calls to a seed method with calls to gauss() may see different
results now.
- The pickle.Pickler class grew a clear_memo() method to mimic that
provided by cPickle.Pickler.
- difflib's SequenceMatcher class now does a dynamic analysis of
which elements are so frequent as to constitute noise. For
comparing files as sequences of lines, this generally works better
than the IS_LINE_JUNK function, and function ndiff's linejunk
argument defaults to None now as a result. A happy benefit is
that SequenceMatcher may run much faster now when applied
to large files with many duplicate lines (for example, C program
text with lots of repeated "}" and "return NULL;" lines).
- New Text.dump() method in Tkinter module.
- New distutils commands for building packagers were added to
support pkgtool on Solaris and swinstall on HP-UX.
- distutils now has a new abstract binary packager base class
command/bdist_packager, which simplifies writing packagers.
This will hopefully provide the missing bits to encourage
people to submit more packagers, e.g. for Debian, FreeBSD
and other systems.
- The UTF-16, -LE and -BE stream readers now raise a
NotImplementedError for all calls to .readline(). Previously, they
used to just produce garbage or fail with an encoding error --
UTF-16 is a 2-byte encoding and the C lib's line reading APIs don't
work well with these.
- compileall now supports quiet operation.
- The BaseHTTPServer now implements optional HTTP/1.1 persistent
connections.
- socket module: the SSL support was broken out of the main
_socket module C helper and placed into a new _ssl helper
which now gets imported by socket.py if available and working.
- encodings package: added aliases for all supported IANA character
sets
- ftplib: to safeguard the user's privacy, anonymous login will use
"anonymous@" as default password, rather than the real user and host
name.
- webbrowser: tightened up the command passed to os.system() so that
arbitrary shell code can't be executed because a bogus URL was
passed in.
- gettext.translation has an optional fallback argument, and
gettext.find an optional all argument. Translations will now fallback
on a per-message basis. The module supports plural forms, by means
of gettext.[d]ngettext and Translation.[u]ngettext.
- distutils bdist commands now offer a --skip-build option.
- warnings.warn now accepts a Warning instance as first argument.
- The xml.sax.expatreader.ExpatParser class will no longer create
circular references by using itself as the locator that gets passed
to the content handler implementation. [SF bug #535474]
- The email.Parser.Parser class now properly parses strings regardless
of their line endings, which can be any of \r, \n, or \r\n (CR, LF,
or CRLF). Also, the Header class's constructor default arguments
has changed slightly so that an explicit maxlinelen value is always
honored, and so unicode conversion error handling can be specified.
- distutils' build_ext command now links C++ extensions with the C++
compiler available in the Makefile or CXX environment variable, if
running under \*nix.
- New module bz2: provides a comprehensive interface for the bz2 compression
library. It implements a complete file interface, one-shot (de)compression
functions, and types for sequential (de)compression.
- New pdb command 'pp' which is like 'p' except that it pretty-prints
the value of its expression argument.
- Now bdist_rpm distutils command understands a verify_script option in
the config file, including the contents of the referred filename in
the "%verifyscript" section of the rpm spec file.
- Fixed bug #495695: webbrowser module would run graphic browsers in a
unix environment even if DISPLAY was not set. Also, support for
skipstone browser was included.
- Fixed bug #636769: rexec would run unallowed code if subclasses of
strings were used as parameters for certain functions.
Tools/Demos
-----------
- pygettext.py now supports globbing on Windows, and accepts module
names in addition to accepting file names.
- The SGI demos (Demo/sgi) have been removed. Nobody thought they
were interesting any more. (The SGI library modules and extensions
are still there; it is believed that at least some of these are
still used and useful.)
- IDLE supports the new encoding declarations (PEP 263); it can also
deal with legacy 8-bit files if they use the locale's encoding. It
allows non-ASCII strings in the interactive shell and executes them
in the locale's encoding.
- freeze.py now produces binaries which can import shared modules,
unlike before when this failed due to missing symbol exports in
the generated binary.
Build
-----
- On Unix, IDLE is now installed automatically.
- The fpectl module is not built by default; it's dangerous or useless
except in the hands of experts.
- The public Python C API will generally be declared using PyAPI_FUNC
and PyAPI_DATA macros, while Python extension module init functions
will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros
are deprecated.
- A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or
get into infinite loops, when a new-style class got garbage-collected.
Unfortunately, to avoid this, the way COUNT_ALLOCS works requires
that new-style classes be immortal in COUNT_ALLOCS builds. Note that
COUNT_ALLOCS is not enabled by default, in either release or debug
builds, and that new-style classes are immortal only in COUNT_ALLOCS
builds.
- Compiling out the cyclic garbage collector is no longer an option.
The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges
that it's always defined (for the benefit of any extension modules
that may be conditionalizing on it). A bonus is that any extension
type participating in cyclic gc can choose to participate in the
Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used
to require editing the core to teach the trashcan mechanism about the
new type.
- According to Annex F of the current C standard,
The Standard C macro HUGE_VAL and its float and long double analogs,
HUGE_VALF and HUGE_VALL, expand to expressions whose values are
positive infinities.
Python only uses the double HUGE_VAL, and only to #define its own symbol
Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL.
pyport.h used to try to worm around that, but the workarounds triggered
other bugs on other platforms, so we gave up. If your platform defines
HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something
that works on your platform. The only instance of this I'm sure about
is on an unknown subset of Cray systems, described here:
http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm
Presumably 2.3a1 breaks such systems. If anyone uses such a system, help!
- The configure option --without-doc-strings can be used to remove the
doc strings from the builtin functions and modules; this reduces the
size of the executable.
- The universal newlines option (PEP 278) is on by default. On Unix
it can be disabled by passing --without-universal-newlines to the
configure script. On other platforms, remove
WITH_UNIVERSAL_NEWLINES from pyconfig.h.
- On Unix, a shared libpython2.3.so can be created with --enable-shared.
- All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS
preprocessor symbols were eliminated. The internal decisions they
controlled stopped being experimental long ago.
- The tools used to build the documentation now work under Cygwin as
well as Unix.
- The bsddb and dbm module builds have been changed to try and avoid version
skew problems and disable linkage with Berkeley DB 1.85 unless the
installer knows what s/he's doing. See the section on building these
modules in the README file for details.
C API
-----
- PyNumber_Check() now returns true for string and unicode objects.
This is a result of these types having a partially defined
tp_as_number slot. (This is not a feature, but an indication that
PyNumber_Check() is not very useful to determine numeric behavior.
It may be deprecated.)
- The string object's layout has changed: the pointer member
ob_sinterned has been replaced by an int member ob_sstate. On some
platforms (e.g. most 64-bit systems) this may change the offset of
the ob_sval member, so as a precaution the API_VERSION has been
incremented. The apparently unused feature of "indirect interned
strings", supported by the ob_sinterned member, is gone. Interned
strings are now usually mortal; there is a new API,
PyString_InternImmortal() that creates immortal interned strings.
(The ob_sstate member can only take three values; however, while
making it a char saves a few bytes per string object on average, in
it also slowed things down a bit because ob_sval was no longer
aligned.)
- The Py_InitModule*() functions now accept NULL for the 'methods'
argument. Modules without global functions are becoming more common
now that factories can be types rather than functions.
- New C API PyUnicode_FromOrdinal() which exposes unichr() at C
level.
- New functions PyErr_SetExcFromWindowsErr() and
PyErr_SetExcFromWindowsErrWithFilename(). Similar to
PyErr_SetFromWindowsErrWithFilename() and
PyErr_SetFromWindowsErr(), but they allow to specify
the exception type to raise. Available on Windows.
- Py_FatalError() is now declared as taking a const char* argument. It
was previously declared without const. This should not affect working
code.
- Added new macro PySequence_ITEM(o, i) that directly calls
sq_item without rechecking that o is a sequence and without
adjusting for negative indices.
- PyRange_New() now raises ValueError if the fourth argument is not 1.
This is part of the removal of deprecated features of the xrange
object.
- PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's
coercion if both arguments have the same type but this type has the
CHECKTYPES flag set. This is to better support proxies.
- The type of tp_free has been changed from "``void (*)(PyObject *)``" to
"``void (*)(void *)``".
- PyObject_Del, PyObject_GC_Del are now functions instead of macros.
- A type can now inherit its metatype from its base type. Previously,
when PyType_Ready() was called, if ob_type was found to be NULL, it
was always set to &PyType_Type; now it is set to base->ob_type,
where base is tp_base, defaulting to &PyObject_Type.
- PyType_Ready() accidentally did not inherit tp_is_gc; now it does.
- The PyCore_* family of APIs have been removed.
- The "u#" parser marker will now pass through Unicode objects as-is
without going through the buffer API.
- The enumerators of cmp_op have been renamed to use the prefix ``PyCmp_``.
- An old #define of ANY as void has been removed from pyport.h. This
hasn't been used since Python's pre-ANSI days, and the #define has
been marked as obsolete since then. SF bug 495548 says it created
conflicts with other packages, so keeping it around wasn't harmless.
- Because Python's magic number scheme broke on January 1st, we decided
to stop Python development. Thanks for all the fish!
- Some of us don't like fish, so we changed Python's magic number
scheme to a new one. See Python/import.c for details.
New platforms
-------------
- OpenVMS is now supported.
- AtheOS is now supported.
- the EMX runtime environment on OS/2 is now supported.
- GNU/Hurd is now supported.
Tests
-----
- The regrtest.py script's -u option now provides a way to say "allow
all resources except this one." For example, to allow everything
except bsddb, give the option '-uall,-bsddb'.
Windows
-------
- The Windows distribution now ships with version 4.0.14 of the
Sleepycat Berkeley database library. This should be a huge
improvement over the previous Berkeley DB 1.85, which had many
bugs.
XXX What are the licensing issues here?
XXX If a user has a database created with a previous version of
XXX Python, what must they do to convert it?
XXX I'm still not sure how to link this thing (see PCbuild/readme.txt).
XXX The version # is likely to change before 2.3a1.
- The Windows distribution now ships with a Secure Sockets Library (SLL)
module (_ssl.pyd)
- The Windows distribution now ships with Tcl/Tk version 8.4.1 (it
previously shipped with Tcl/Tk 8.3.2).
- When Python is built under a Microsoft compiler, sys.version now
includes the compiler version number (_MSC_VER). For example, under
MSVC 6, sys.version contains the substring "MSC v.1200 ". 1200 is
the value of _MSC_VER under MSVC 6.
- Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause
of that has been fixed in the installer (disabled Wise's "delete in-
use files" uninstall option).
- Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031]
- The installer now installs Start menu shortcuts under (the local
equivalent of) "All Users" when doing an Admin install.
- file.truncate([newsize]) now works on Windows for all newsize values.
It used to fail if newsize didn't fit in 32 bits, reflecting a
limitation of MS _chsize (which is no longer used).
- os.waitpid() is now implemented for Windows, and can be used to block
until a specified process exits. This is similar to, but not exactly
the same as, os.waitpid() on POSIX systems. If you're waiting for
a specific process whose pid was obtained from one of the spawn()
functions, the same Python os.waitpid() code works across platforms.
See the docs for details. The docs were changed to clarify that
spawn functions return, and waitpid requires, a process handle on
Windows (not the same thing as a Windows process id).
- New tempfile.TemporaryFile implementation for Windows: this doesn't
need a TemporaryFileWrapper wrapper anymore, and should be immune
to a nasty problem: before 2.3, if you got a temp file on Windows, it
got wrapped in an object whose close() method first closed the
underlying file, then deleted the file. This usually worked fine.
However, the spawn family of functions on Windows create (at a low C
level) the same set of open files in the spawned process Q as were
open in the spawning process P. If a temp file f was among them, then
doing f.close() in P first closed P's C-level file handle on f, but Q's
C-level file handle on f remained open, so the attempt in P to delete f
blew up with a "Permission denied" error (Windows doesn't allow
deleting open files). This was surprising, subtle, and difficult to
work around.
- The os module now exports all the symbolic constants usable with the
low-level os.open() on Windows: the new constants in 2.3 are
O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL.
The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT,
O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary
to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY
(so specify both if you want both; note that neither is useful unless
specified with O_CREAT too).
Mac
----
- Mac/Relnotes is gone, the release notes are now here.
- Python (the OSX-only, unix-based version, not the OS9-compatible CFM
version) now fully supports unicode strings as arguments to various file
system calls, eg. open(), file(), os.stat() and os.listdir().
- The current naming convention for Python on the Macintosh is that MacPython
refers to the unix-based OSX-only version, and MacPython-OS9 refers to the
CFM-based version that runs on both OS9 and OSX.
- All MacPython-OS9 functionality is now available in an OSX unix build,
including the Carbon modules, the IDE, OSA support, etc. A lot of this
will only work correctly in a framework build, though, because you cannot
talk to the window manager unless your application is run from a .app
bundle. There is a command line tool "pythonw" that runs your script
with an interpreter living in such a .app bundle, this interpreter should
be used to run any Python script using the window manager (including
Tkinter or wxPython scripts).
- Most of Mac/Lib has moved to Lib/plat-mac, which is again used both in
MacPython-OSX and MacPython-OS9. The only modules remaining in Mac/Lib
are specifically for MacPython-OS9 (CFM support, preference resources, etc).
- A new utility PythonLauncher will start a Python interpreter when a .py or
.pyw script is double-clicked in the Finder. By default .py scripts are
run with a normal Python interpreter in a Terminal window and .pyw
files are run with a window-aware pythonw interpreter without a Terminal
window, but all this can be customized.
- MacPython-OS9 is now Carbon-only, so it runs on Mac OS 9 or Mac OS X and
possibly on Mac OS 8.6 with the right CarbonLib installed, but not on earlier
releases.
- Many tools such as BuildApplet.py and gensuitemodule.py now support a command
line interface too.
- All the Carbon classes are now PEP253 compliant, meaning that you can
subclass them from Python. Most of the attributes have gone, you should
now use the accessor function call API, which is also what Apple's
documentation uses. Some attributes such as grafport.visRgn are still
available for convenience.
- New Carbon modules File (implementing the APIs in Files.h and Aliases.h)
and Folder (APIs from Folders.h). The old macfs builtin module is
gone, and replaced by a Python wrapper around the new modules.
- Pathname handling should now be fully consistent: MacPython-OSX always uses
unix pathnames and MacPython-OS9 always uses colon-separated Mac pathnames
(also when running on Mac OS X).
- New Carbon modules Help and AH give access to the Carbon Help Manager.
There are hooks in the IDE to allow accessing the Python documentation
(and Apple's Carbon and Cocoa documentation) through the Help Viewer.
See Mac/OSX/README for converting the Python documentation to a
Help Viewer compatible form and installing it.
- OSA support has been redesigned and the generated Python classes now
mirror the inheritance defined by the underlying OSA classes.
- MacPython no longer maps both \r and \n to \n on input for any text file.
This feature has been replaced by universal newline support (PEP278).
- The default encoding for Python sourcefiles in MacPython-OS9 is no longer
mac-roman (or whatever your local Mac encoding was) but "ascii", like on
other platforms. If you really need sourcefiles with Mac characters in them
you can change this in site.py.
What's New in Python 2.2 final?
===============================
*Release date: 21-Dec-2001*
Type/class unification and new-style classes
--------------------------------------------
- pickle.py, cPickle: allow pickling instances of new-style classes
with a custom metaclass.
Core and builtins
-----------------
- weakref proxy object: when comparing, unwrap both arguments if both
are proxies.
Extension modules
-----------------
- binascii.b2a_base64(): fix a potential buffer overrun when encoding
very short strings.
- cPickle: the obscure "fast" mode was suspected of causing stack
overflows on the Mac. Hopefully fixed this by setting the recursion
limit much smaller. If the limit is too low (it only affects
performance), you can change it by defining PY_CPICKLE_FAST_LIMIT
when compiling cPickle.c (or in pyconfig.h).
Library
-------
- dumbdbm.py: fixed a dumb old bug (the file didn't get synched at
close or delete time).
- rfc822.py: fixed a bug where the address '<>' was converted to None
instead of an empty string (also fixes the email.Utils module).
- xmlrpclib.py: version 1.0.0; uses precision for doubles.
- test suite: the pickle and cPickle tests were not executing any code
when run from the standard regression test.
Tools/Demos
-----------
Build
-----
C API
-----
New platforms
-------------
Tests
-----
Windows
-------
- distutils package: fixed broken Windows installers (bdist_wininst).
- tempfile.py: prevent mysterious warnings when TemporaryFileWrapper
instances are deleted at process exit time.
- socket.py: prevent mysterious warnings when socket instances are
deleted at process exit time.
- posixmodule.c: fix a Windows crash with stat() of a filename ending
in backslash.
Mac
----
- The Carbon toolbox modules have been upgraded to Universal Headers
3.4, and experimental CoreGraphics and CarbonEvents modules have
been added. All only for framework-enabled MacOSX.
What's New in Python 2.2c1?
===========================
*Release date: 14-Dec-2001*
Type/class unification and new-style classes
--------------------------------------------
- Guido's tutorial introduction to the new type/class features has
been extensively updated. See
http://www.python.org/2.2/descrintro.html
That remains the primary documentation in this area.
- Fixed a leak: instance variables declared with __slots__ were never
deleted!
- The "delete attribute" method of descriptor objects is called
__delete__, not __del__. In previous releases, it was mistakenly
called __del__, which created an unfortunate overloading condition
with finalizers. (The "get attribute" and "set attribute" methods
are still called __get__ and __set__, respectively.)
- Some subtle issues with the super built-in were fixed:
(a) When super itself is subclassed, its __get__ method would still
return an instance of the base class (i.e., of super).
(b) super(C, C()).__class__ would return C rather than super. This
is confusing. To fix this, I decided to change the semantics of
super so that it only applies to code attributes, not to data
attributes. After all, overriding data attributes is not
supported anyway.
(c) The __get__ method didn't check whether the argument was an
instance of the type used in creation of the super instance.
- Previously, hash() of an instance of a subclass of a mutable type
(list or dictionary) would return some value, rather than raising
TypeError. This has been fixed. Also, directly calling
dict.__hash__ and list.__hash__ now raises the same TypeError
(previously, these were the same as object.__hash__).
- New-style objects now support deleting their __dict__. This is for
all intents and purposes equivalent to assigning a brand new empty
dictionary, but saves space if the object is not used further.
Core and builtins
-----------------
- -Qnew now works as documented in PEP 238: when -Qnew is passed on
the command line, all occurrences of "/" use true division instead
of classic division. See the PEP for details. Note that "all"
means all instances in library and 3rd-party modules, as well as in
your own code. As the PEP says, -Qnew is intended for use only in
educational environments with control over the libraries in use.
Note that test_coercion.py in the standard Python test suite fails
under -Qnew; this is expected, and won't be repaired until true
division becomes the default (in the meantime, test_coercion is
testing the current rules).
- complex() now only allows the first argument to be a string
argument, and raises TypeError if either the second arg is a string
or if the second arg is specified when the first is a string.
Extension modules
-----------------
- gc.get_referents was renamed to gc.get_referrers.
Library
-------
- Functions in the os.spawn() family now release the global interpreter
lock around calling the platform spawn. They should always have done
this, but did not before 2.2c1. Multithreaded programs calling
an os.spawn function with P_WAIT will no longer block all Python threads
until the spawned program completes. It's possible that some programs
relies on blocking, although more likely by accident than by design.
- webbrowser defaults to netscape.exe on OS/2 now.
- Tix.ResizeHandle exposes detach_widget, hide, and show.
- The charset alias windows_1252 has been added.
- types.StringTypes is a tuple containing the defined string types;
usually this will be (str, unicode), but if Python was compiled
without Unicode support it will be just (str,).
- The pulldom and minidom modules were synchronized to PyXML.
Tools/Demos
-----------
- A new script called Tools/scripts/google.py was added, which fires
off a search on Google.
Build
-----
- Note that release builds of Python should arrange to define the
preprocessor symbol NDEBUG on the command line (or equivalent).
In the 2.2 pre-release series we tried to define this by magic in
Python.h instead, but it proved to cause problems for extension
authors. The Unix, Windows and Mac builds now all define NDEBUG in
release builds via cmdline (or equivalent) instead. Ports to
other platforms should do likewise.
- It is no longer necessary to use --with-suffix when building on a
case-insensitive file system (such as Mac OS X HFS+). In the build
directory an extension is used, but not in the installed python.
C API
-----
- New function PyDict_MergeFromSeq2() exposes the builtin dict
constructor's logic for updating a dictionary from an iterable object
producing key-value pairs.
- PyArg_ParseTupleAndKeywords() requires that the number of entries in
the keyword list equal the number of argument specifiers. This
wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even
dump core in some bad cases. This has been repaired. As a result,
PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that
previously went unchallenged.
New platforms
-------------
Tests
-----
Windows
-------
Mac
----
- In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin",
without any trailing digits.
- Changed logic for finding python home in Mac OS X framework Pythons.
Now sys.executable points to the executable again, in stead of to
the shared library. The latter is used only for locating the python
home.
What's New in Python 2.2b2?
===========================
*Release date: 16-Nov-2001*
Type/class unification and new-style classes
--------------------------------------------
- Multiple inheritance mixing new-style and classic classes in the
list of base classes is now allowed, so this works now:
class Classic: pass
class Mixed(Classic, object): pass
The MRO (method resolution order) for each base class is respected
according to its kind, but the MRO for the derived class is computed
using new-style MRO rules if any base class is a new-style class.
This needs to be documented.
- The new builtin dictionary() constructor, and dictionary type, have
been renamed to dict. This reflects a decade of common usage.
- dict() now accepts an iterable object producing 2-sequences. For
example, dict(d.items()) == d for any dictionary d. The argument,
and the elements of the argument, can be any iterable objects.
- New-style classes can now have a __del__ method, which is called
when the instance is deleted (just like for classic classes).
- Assignment to object.__dict__ is now possible, for objects that are
instances of new-style classes that have a __dict__ (unless the base
class forbids it).
- Methods of built-in types now properly check for keyword arguments
(formerly these were silently ignored). The only built-in methods
that take keyword arguments are __call__, __init__ and __new__.
- The socket function has been converted to a type; see below.
Core and builtins
-----------------
- Assignment to __debug__ raises SyntaxError at compile-time. This
was promised when 2.1c1 was released as "What's New in Python 2.1c1"
(see below) says.
- Clarified the error messages for unsupported operands to an operator
(like 1 + '').
Extension modules
-----------------
- mmap has a new keyword argument, "access", allowing a uniform way for
both Windows and Unix users to create read-only, write-through and
copy-on-write memory mappings. This was previously possible only on
Unix. A new keyword argument was required to support this in a
uniform way because the mmap() signatures had diverged across
platforms. Thanks to Jay T Miller for repairing this!
- By default, the gc.garbage list now contains only those instances in
unreachable cycles that have __del__ methods; in 2.1 it contained all
instances in unreachable cycles. "Instances" here has been generalized
to include instances of both new-style and old-style classes.
- The socket module defines a new method for socket objects,
sendall(). This is like send() but may make multiple calls to
send() until all data has been sent. Also, the socket function has
been converted to a subclassable type, like list and tuple (etc.)
before it; socket and SocketType are now the same thing.
- Various bugfixes to the curses module. There is now a test suite
for the curses module (you have to run it manually).
- binascii.b2a_base64 no longer places an arbitrary restriction of 57
bytes on its input.
Library
-------
- tkFileDialog exposes a Directory class and askdirectory
convenience function.
- Symbolic group names in regular expressions must be unique. For
example, the regexp r'(?P<abc>)(?P<abc>)' is not allowed, because a
single name can't mean both "group 1" and "group 2" simultaneously.
Python 2.2 detects this error at regexp compilation time;
previously, the error went undetected, and results were
unpredictable. Also in sre, the pattern.split(), pattern.sub(), and
pattern.subn() methods have been rewritten in C. Also, an
experimental function/method finditer() has been added, which works
like findall() but returns an iterator.
- Tix exposes more commands through the classes DirSelectBox,
DirSelectDialog, ListNoteBook, Meter, CheckList, and the
methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog,
tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions.
- Traceback objects are now scanned by cyclic garbage collection, so
cycles created by casual use of sys.exc_info() no longer cause
permanent memory leaks (provided garbage collection is enabled).
- os.extsep -- a new variable needed by the RISCOS support. It is the
separator used by extensions, and is '.' on all platforms except
RISCOS, where it is '/'. There is no need to use this variable
unless you have a masochistic desire to port your code to RISCOS.
- mimetypes.py has optional support for non-standard, but commonly
found types. guess_type() and guess_extension() now accept an
optional 'strict' flag, defaulting to true, which controls whether
recognize non-standard types or not. A few non-standard types we
know about have been added. Also, when run as a script, there are
new -l and -e options.
- statcache is now deprecated.
- email.Utils.formatdate() now produces the preferred RFC 2822 style
dates with numeric timezones (it used to produce obsolete dates
hard coded to "GMT" timezone). An optional 'localtime' flag is
added to produce dates in the local timezone, with daylight savings
time properly taken into account.
- In pickle and cPickle, instead of masking errors in load() by
transforming them into SystemError, we let the original exception
propagate out. Also, implement support for __safe_for_unpickling__
in pickle, as it already was supported in cPickle.
Tools/Demos
-----------
Build
-----
- The dbm module is built using libdb1 if available. The bsddb module
is built with libdb3 if available.
- Misc/Makefile.pre.in has been removed by BDFL pronouncement.
C API
-----
- New function PySequence_Fast_GET_SIZE() returns the size of a non-
NULL result from PySequence_Fast(), more quickly than calling
PySequence_Size().
- New argument unpacking function PyArg_UnpackTuple() added.
- New functions PyObject_CallFunctionObjArgs() and
PyObject_CallMethodObjArgs() have been added to make it more
convenient and efficient to call functions and methods from C.
- PyArg_ParseTupleAndKeywords() no longer masks errors, so it's
possible that this will propagate errors it didn't before.
- New function PyObject_CheckReadBuffer(), which returns true if its
argument supports the single-segment readable buffer interface.
New platforms
-------------
- We've finally confirmed that this release builds on HP-UX 11.00,
*with* threads, and passes the test suite.
- Thanks to a series of patches from Michael Muller, Python may build
again under OS/2 Visual Age C++.
- Updated RISCOS port by Dietmar Schwertberger.
Tests
-----
- Added a test script for the curses module. It isn't run automatically;
regrtest.py must be run with '-u curses' to enable it.
Windows
-------
Mac
----
- PythonScript has been moved to unsupported and is slated to be
removed completely in the next release.
- It should now be possible to build applets that work on both OS9 and
OSX.
- The core is now linked with CoreServices not Carbon; as a side
result, default 8bit encoding on OSX is now ASCII.
- Python should now build on OSX 10.1.1
What's New in Python 2.2b1?
===========================
*Release date: 19-Oct-2001*
Type/class unification and new-style classes
--------------------------------------------
- New-style classes are now always dynamic (except for built-in and
extension types). There is no longer a performance penalty, and I
no longer see another reason to keep this baggage around. One relic
remains: the __dict__ of a new-style class is a read-only proxy; you
must set the class's attribute to modify it. As a consequence, the
__defined__ attribute of new-style types no longer exists, for lack
of need: there is once again only one __dict__ (although in the
future a __cache__ may be resurrected with a similar function, if I
can prove that it actually speeds things up).
- C.__doc__ now works as expected for new-style classes (in 2.2a4 it
always returned None, even when there was a class docstring).
- doctest now finds and runs docstrings attached to new-style classes,
class methods, static methods, and properties.
Core and builtins
-----------------
- A very subtle syntactical pitfall in list comprehensions was fixed.
For example: [a+b for a in 'abc', for b in 'def']. The comma in
this example is a mistake. Previously, this would silently let 'a'
iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce',
'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be',
'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error.
Note that [a for a in <singleton>] is a convoluted way to say
[<singleton>] anyway, so it's not like any expressiveness is lost.
- getattr(obj, name, default) now only catches AttributeError, as
documented, rather than returning the default value for all
exceptions (which could mask bugs in a __getattr__ hook, for
example).
- Weak reference objects are now part of the core and offer a C API.
A bug which could allow a core dump when binary operations involved
proxy reference has been fixed. weakref.ReferenceError is now a
built-in exception.
- unicode(obj) now behaves more like str(obj), accepting arbitrary
objects, and calling a __unicode__ method if it exists.
unicode(obj, encoding) and unicode(obj, encoding, errors) still
require an 8-bit string or character buffer argument.
- isinstance() now allows any object as the first argument and a
class, a type or something with a __bases__ tuple attribute for the
second argument. The second argument may also be a tuple of a
class, type, or something with __bases__, in which case isinstance()
will return true if the first argument is an instance of any of the
things contained in the second argument tuple. E.g.
isinstance(x, (A, B))
returns true if x is an instance of A or B.
Extension modules
-----------------
- thread.start_new_thread() now returns the thread ID (previously None).
- binascii has now two quopri support functions, a2b_qp and b2a_qp.
- readline now supports setting the startup_hook and the
pre_event_hook, and adds the add_history() function.
- os and posix supports chroot(), setgroups() and unsetenv() where
available. The stat(), fstat(), statvfs() and fstatvfs() functions
now return "pseudo-sequences" -- the various fields can now be
accessed as attributes (e.g. os.stat("/").st_mtime) but for
backwards compatibility they also behave as a fixed-length sequence.
Some platform-specific fields (e.g. st_rdev) are only accessible as
attributes.
- time: localtime(), gmtime() and strptime() now return a
pseudo-sequence similar to the os.stat() return value, with
attributes like tm_year etc.
- Decompression objects in the zlib module now accept an optional
second parameter to decompress() that specifies the maximum amount
of memory to use for the uncompressed data.
- optional SSL support in the socket module now exports OpenSSL
functions RAND_add(), RAND_egd(), and RAND_status(). These calls
are useful on platforms like Solaris where OpenSSL does not
automatically seed its PRNG. Also, the keyfile and certfile
arguments to socket.ssl() are now optional.
- posixmodule (and by extension, the os module on POSIX platforms) now
exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW.
Library
-------
- doctest now excludes functions and classes not defined by the module
being tested, thanks to Tim Hochberg.
- HotShot, a new profiler implemented using a C-based callback, has
been added. This substantially reduces the overhead of profiling,
but it is still quite preliminary. Support modules and
documentation will be added in upcoming releases (before 2.2 final).
- profile now produces correct output in situations where an exception
raised in Python is cleared by C code (e.g. hasattr()). This used
to cause wrong output, including spurious claims of recursive
functions and attribution of time spent to the wrong function.
The code and documentation for the derived OldProfile and HotProfile
profiling classes was removed. The code hasn't worked for years (if
you tried to use them, they raised exceptions). OldProfile
intended to reproduce the behavior of the profiler Python used more
than 7 years ago, and isn't interesting anymore. HotProfile intended
to provide a faster profiler (but producing less information), and
that's a worthy goal we intend to meet via a different approach (but
without losing information).
- Profile.calibrate() has a new implementation that should deliver
a much better system-specific calibration constant. The constant can
now be specified in an instance constructor, or as a Profile class or
instance variable, instead of by editing profile.py's source code.
Calibration must still be done manually (see the docs for the profile
module).
Note that Profile.calibrate() must be overridden by subclasses.
Improving the accuracy required exploiting detailed knowledge of
profiler internals; the earlier method abstracted away the details
and measured a simplified model instead, but consequently computed
a constant too small by a factor of 2 on some modern machines.
- quopri's encode and decode methods take an optional header parameter,
which indicates whether output is intended for the header 'Q'
encoding.
- The SocketServer.ThreadingMixIn class now closes the request after
finish_request() returns. (Not when it errors out though.)
- The nntplib module's NNTP.body() method has grown a 'file' argument
to allow saving the message body to a file.
- The email package has added a class email.Parser.HeaderParser which
only parses headers and does not recurse into the message's body.
Also, the module/class MIMEAudio has been added for representing
audio data (contributed by Anthony Baxter).
- ftplib should be able to handle files > 2GB.
- ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO,
ON, and OFF.
- xml.dom.minidom NodeList objects now support the length attribute
and item() method as required by the DOM specifications.
Tools/Demos
-----------
- Demo/dns was removed. It no longer serves any purpose; a package
derived from it is now maintained by Anthony Baxter, see
http://PyDNS.SourceForge.net.
- The freeze tool has been made more robust, and two new options have
been added: -X and -E.
Build
-----
- configure will use CXX in LINKCC if CXX is used to build main() and
the system requires to link a C++ main using the C++ compiler.
C API
-----
- The documentation for the tp_compare slot is updated to require that
the return value must be -1, 0, 1; an arbitrary number <0 or >0 is
not correct. This is not yet enforced but will be enforced in
Python 2.3; even later, we may use -2 to indicate errors and +2 for
"NotImplemented". Right now, -1 should be used for an error return.
- PyLong_AsLongLong() now accepts int (as well as long) arguments.
Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well
as long) arguments.
- PyThread_start_new_thread() now returns a long int giving the thread
ID, if one can be calculated; it returns -1 for error, 0 if no
thread ID is calculated (this is an incompatible change, but only
the thread module used this API). This code has only really been
tested on Linux and Windows; other platforms please beware (and
report any bugs or strange behavior).
- PyUnicode_FromEncodedObject() no longer accepts Unicode objects as
input.
New platforms
-------------
Tests
-----
Windows
-------
- Installer: If you install IDLE, and don't disable file-extension
registration, a new "Edit with IDLE" context (right-click) menu entry
is created for .py and .pyw files.
- The signal module now supports SIGBREAK on Windows, thanks to Steven
Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK
action remains to call Win32 ExitProcess(). This can be changed via
signal.signal(). For example::
# Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C
# (SIGINT) behavior.
import signal
signal.signal(signal.SIGBREAK, signal.default_int_handler)
try:
while 1:
pass
except KeyboardInterrupt:
# We get here on Ctrl+C or Ctrl+Break now; if we had not changed
# SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the
# program without the possibility for any Python-level cleanup).
print "Clean exit"
What's New in Python 2.2a4?
===========================
*Release date: 28-Sep-2001*
Type/class unification and new-style classes
--------------------------------------------
- pydoc and inspect are now aware of new-style classes;
e.g. help(list) at the interactive prompt now shows proper
documentation for all operations on list objects.
- Applications using Jim Fulton's ExtensionClass module can now safely
be used with Python 2.2. In particular, Zope 2.4.1 now works with
Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass
examples also work again. It is hoped that Gtk and Boost also work
with 2.2a4 and beyond. (If you can confirm this, please write
webmaster@python.org; if there are still problems, please open a bug
report on SourceForge.)
- property() now takes 4 keyword arguments: fget, fset, fdel and doc.
These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__'
in the constructed property object. fget, fset and fdel weren't
discoverable from Python in 2.2a3. __doc__ is new, and allows to
associate a docstring with a property.
- Comparison overloading is now more completely implemented. For
example, a str subclass instance can properly be compared to a str
instance, and it can properly overload comparison. Ditto for most
other built-in object types.
- The repr() of new-style classes has changed; instead of <type
'M.Foo'> a new-style class is now rendered as <class 'M.Foo'>,
*except* for built-in types, which are still rendered as <type
'Foo'> (to avoid upsetting existing code that might parse or
otherwise rely on repr() of certain type objects).
- The repr() of new-style objects is now always <Foo object at XXX>;
previously, it was sometimes <Foo instance at XXX>.
- For new-style classes, what was previously called __getattr__ is now
called __getattribute__. This method, if defined, is called for
*every* attribute access. A new __getattr__ hook more similar to the
one in classic classes is defined which is called only if regular
attribute access raises AttributeError; to catch *all* attribute
access, you can use __getattribute__ (for new-style classes). If
both are defined, __getattribute__ is called first, and if it raises
AttributeError, __getattr__ is called.
- The __class__ attribute of new-style objects can be assigned to.
The new class must have the same C-level object layout as the old
class.
- The builtin file type can be subclassed now. In the usual pattern,
"file" is the name of the builtin type, and file() is a new builtin
constructor, with the same signature as the builtin open() function.
file() is now the preferred way to open a file.
- Previously, __new__ would only see sequential arguments passed to
the type in a constructor call; __init__ would see both sequential
and keyword arguments. This made no sense whatsoever any more, so
now both __new__ and __init__ see all arguments.
- Previously, hash() applied to an instance of a subclass of str or
unicode always returned 0. This has been repaired.
- Previously, an operation on an instance of a subclass of an
immutable type (int, long, float, complex, tuple, str, unicode),
where the subtype didn't override the operation (and so the
operation was handled by the builtin type), could return that
instance instead a value of the base type. For example, if s was of
a str subclass type, s[:] returned s as-is. Now it returns a str
with the same value as s.
- Provisional support for pickling new-style objects has been added.
Core
----
- file.writelines() now accepts any iterable object producing strings.
- PyUnicode_FromEncodedObject() now works very much like
PyObject_Str(obj) in that it tries to use __str__/tp_str
on the object if the object is not a string or buffer. This
makes unicode() behave like str() when applied to non-string/buffer
objects.
- PyFile_WriteObject now passes Unicode objects to the file's write
method. As a result, all file-like objects which may be the target
of a print statement must support Unicode objects, i.e. they must
at least convert them into ASCII strings.
- Thread scheduling on Solaris should be improved; it is no longer
necessary to insert a small sleep at the start of a thread in order
to let other runnable threads be scheduled.
Library
-------
- StringIO.StringIO instances and cStringIO.StringIO instances support
read character buffer compatible objects for their .write() methods.
These objects are converted to strings and then handled as such
by the instances.
- The "email" package has been added. This is basically a port of the
mimelib package <http://sf.net/projects/mimelib> with API changes
and some implementations updated to use iterators and generators.
- difflib.ndiff() and difflib.Differ.compare() are generators now. This
restores the ability of Tools/scripts/ndiff.py to start producing output
before the entire comparison is complete.
- StringIO.StringIO instances and cStringIO.StringIO instances support
iteration just like file objects (i.e. their .readline() method is
called for each iteration until it returns an empty string).
- The codecs module has grown four new helper APIs to access
builtin codecs: getencoder(), getdecoder(), getreader(),
getwriter().
- SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer)
simplifies writing XML RPC servers.
- os.path.realpath(): a new function that returns the absolute pathname
after interpretation of symbolic links. On non-Unix systems, this
is an alias for os.path.abspath().
- operator.indexOf() (PySequence_Index() in the C API) now works with any
iterable object.
- smtplib now supports various authentication and security features of
the SMTP protocol through the new login() and starttls() methods.
- hmac: a new module implementing keyed hashing for message
authentication.
- mimetypes now recognizes more extensions and file types. At the
same time, some mappings not sanctioned by IANA were removed.
- The "compiler" package has been brought up to date to the state of
Python 2.2 bytecode generation. It has also been promoted from a
Tool to a standard library package. (Tools/compiler still exists as
a sample driver.)
Build
-----
- Large file support (LFS) is now automatic when the platform supports
it; no more manual configuration tweaks are needed. On Linux, at
least, it's possible to have a system whose C library supports large
files but whose kernel doesn't; in this case, large file support is
still enabled but doesn't do you any good unless you upgrade your
kernel or share your Python executable with another system whose
kernel has large file support.
- The configure script now supplies plausible defaults in a
cross-compilation environment. This doesn't mean that the supplied
values are always correct, or that cross-compilation now works
flawlessly -- but it's a first step (and it shuts up most of
autoconf's warnings about AC_TRY_RUN).
- The Unix build is now a bit less chatty, courtesy of the parser
generator. The build is completely silent (except for errors) when
using "make -s", thanks to a -q option to setup.py.
C API
-----
- The "structmember" API now supports some new flag bits to deny read
and/or write access to attributes in restricted execution mode.
New platforms
-------------
- Compaq's iPAQ handheld, running the "familiar" Linux distribution
(http://familiar.handhelds.org).
Tests
-----
- The "classic" standard tests, which work by comparing stdout to
an expected-output file under Lib/test/output/, no longer stop at
the first mismatch. Instead the test is run to completion, and a
variant of ndiff-style comparison is used to report all differences.
This is much easier to understand than the previous style of reporting.
- The unittest-based standard tests now use regrtest's test_main()
convention, instead of running as a side-effect of merely being
imported. This allows these tests to be run in more natural and
flexible ways as unittests, outside the regrtest framework.
- regrtest.py is much better integrated with unittest and doctest now,
especially in regard to reporting errors.
Windows
-------
- Large file support now also works for files > 4GB, on filesystems
that support it (NTFS under Windows 2000). See "What's New in
Python 2.2a3" for more detail.
What's New in Python 2.2a3?
===========================
*Release Date: 07-Sep-2001*
Core
----
- Conversion of long to float now raises OverflowError if the long is too
big to represent as a C double.
- The 3-argument builtin pow() no longer allows a third non-None argument
if either of the first two arguments is a float, or if both are of
integer types and the second argument is negative (in which latter case
the arguments are converted to float, so this is really the same
restriction).
- The builtin dir() now returns more information, and sometimes much
more, generally naming all attributes of an object, and all attributes
reachable from the object via its class, and from its class's base
classes, and so on from them too. Example: in 2.2a2, dir([]) returned
an empty list. In 2.2a3,
>>> dir([])
['__add__', '__class__', '__contains__', '__delattr__', '__delitem__',
'__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__',
'__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__',
'__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__',
'__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__',
'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove',
'reverse', 'sort']
dir(module) continues to return only the module's attributes, though.
- Overflowing operations on plain ints now return a long int rather
than raising OverflowError. This is a partial implementation of PEP
237. You can use -Wdefault::OverflowWarning to enable a warning for
this situation, and -Werror::OverflowWarning to revert to the old
OverflowError exception.
- A new command line option, -Q<arg>, is added to control run-time
warnings for the use of classic division. (See PEP 238.) Possible
values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is
-Qold, meaning the / operator has its classic meaning and no
warnings are issued. Using -Qwarn issues a run-time warning about
all uses of classic division for int and long arguments; -Qwarnall
also warns about classic division for float and complex arguments
(for use with fixdiv.py).
[Note: the remainder of this item (preserved below) became
obsolete in 2.2c1 -- -Qnew has global effect in 2.2] ::
Using -Qnew is questionable; it turns on new division by default, but
only in the __main__ module. You can usefully combine -Qwarn or
-Qwarnall and -Qnew: this gives the __main__ module new division, and
warns about classic division everywhere else.
- Many built-in types can now be subclassed. This applies to int,
long, float, str, unicode, and tuple. (The types complex, list and
dictionary can also be subclassed; this was introduced earlier.)
Note that restrictions apply when subclassing immutable built-in
types: you can only affect the value of the instance by overloading
__new__. You can add mutable attributes, and the subclass instances
will have a __dict__ attribute, but you cannot change the "value"
(as implemented by the base class) of an immutable subclass instance
once it is created.
- The dictionary constructor now takes an optional argument, a
mapping-like object, and initializes the dictionary from its
(key, value) pairs.
- A new built-in type, super, has been added. This facilitates making
"cooperative super calls" in a multiple inheritance setting. For an
explanation, see http://www.python.org/2.2/descrintro.html#cooperation
- A new built-in type, property, has been added. This enables the
creation of "properties". These are attributes implemented by
getter and setter functions (or only one of these for read-only or
write-only attributes), without the need to override __getattr__.
See http://www.python.org/2.2/descrintro.html#property
- The syntax of floating-point and imaginary literals has been
liberalized, to allow leading zeroes. Examples of literals now
legal that were SyntaxErrors before:
00.0 0e3 0100j 07.5 00000000000000000008.
- An old tokenizer bug allowed floating point literals with an incomplete
exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError.
Library
-------
- telnetlib includes symbolic names for the options, and support for
setting an option negotiation callback. It also supports processing
of suboptions.
- The new C standard no longer requires that math libraries set errno to
ERANGE on overflow. For platform libraries that exploit this new
freedom, Python's overflow-checking was wholly broken. A new overflow-
checking scheme attempts to repair that, but may not be reliable on all
platforms (C doesn't seem to provide anything both useful and portable
in this area anymore).
- Asynchronous timeout actions are available through the new class
threading.Timer.
- math.log and math.log10 now return sensible results for even huge
long arguments. For example, math.log10(10 ** 10000) ~= 10000.0.
- A new function, imp.lock_held(), returns 1 when the import lock is
currently held. See the docs for the imp module.
- pickle, cPickle and marshal on 32-bit platforms can now correctly read
dumps containing ints written on platforms where Python ints are 8 bytes.
When read on a box where Python ints are 4 bytes, such values are
converted to Python longs.
- In restricted execution mode (using the rexec module), unmarshalling
code objects is no longer allowed. This plugs a security hole.
- unittest.TestResult instances no longer store references to tracebacks
generated by test failures. This prevents unexpected dangling references
to objects that should be garbage collected between tests.
Tools
-----
- Tools/scripts/fixdiv.py has been added which can be used to fix
division operators as per PEP 238.
Build
-----
- If you are an adventurous person using Mac OS X you may want to look at
Mac/OSX. There is a Makefile there that will build Python as a real Mac
application, which can be used for experimenting with Carbon or Cocoa.
Discussion of this on pythonmac-sig, please.
C API
-----
- New function PyObject_Dir(obj), like Python __builtin__.dir(obj).
- Note that PyLong_AsDouble can fail! This has always been true, but no
callers checked for it. It's more likely to fail now, because overflow
errors are properly detected now. The proper way to check::
double x = PyLong_AsDouble(some_long_object);
if (x == -1.0 && PyErr_Occurred()) {
/* The conversion failed. */
}
- The GC API has been changed. Extensions that use the old API will still
compile but will not participate in GC. To upgrade an extension
module:
- rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC
- use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and
PyObject_GC_Del to deallocate them
- rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini
to PyObject_GC_UnTrack
- remove PyGC_HEAD_SIZE from object size calculations
- remove calls to PyObject_AS_GC and PyObject_FROM_GC
- Two new functions: PyString_FromFormat() and PyString_FromFormatV().
These can be used safely to construct string objects from a
sprintf-style format string (similar to the format string supported
by PyErr_Format()).
New platforms
-------------
- Stephen Hansen contributed patches sufficient to get a clean compile
under Borland C (Windows), but he reports problems running it and ran
out of time to complete the port. Volunteers? Expect a MemoryError
when importing the types module; this is probably shallow, and
causing later failures too.
Tests
-----
Windows
-------
- Large file support is now enabled on Win32 platforms as well as on
Win64. This means that, for example, you can use f.tell() and f.seek()
to manipulate files larger than 2 gigabytes (provided you have enough
disk space, and are using a Windows filesystem that supports large
partitions). Windows filesystem limits: FAT has a 2GB (gigabyte)
filesize limit, and large file support makes no difference there.
FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now.
NTFS has no practical limit on file size, and files of any size can be
used from Python now.
- The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC
points to command.com (patch from Brian Quinlan).
What's New in Python 2.2a2?
===========================
*Release Date: 22-Aug-2001*
Build
-----
- Tim Peters developed a brand new Windows installer using Wise 8.1,
generously donated to us by Wise Solutions.
- configure supports a new option --enable-unicode, with the values
ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode
type and supporting code is completely removed from the interpreter.
- A new configure option --enable-framework builds a Mac OS X framework,
which "make frameworkinstall" will install. This provides a starting
point for more mac-like functionality, join pythonmac-sig@python.org
if you are interested in helping.
- The NeXT platform is no longer supported.
- The 'new' module is now statically linked.
Tools
-----
- The new Tools/scripts/cleanfuture.py can be used to automatically
edit out obsolete future statements from Python source code. See
the module docstring for details.
Tests
-----
- regrtest.py now knows which tests are expected to be skipped on some
platforms, allowing to give clearer test result output. regrtest
also has optional --use/-u switch to run normally disabled tests
which require network access or consume significant disk resources.
- Several new tests in the standard test suite, with special thanks to
Nick Mathewson.
Core
----
- The floor division operator // has been added as outlined in PEP
238. The / operator still provides classic division (and will until
Python 3.0) unless "from __future__ import division" is included, in
which case the / operator will provide true division. The operator
module provides truediv() and floordiv() functions. Augmented
assignment variants are included, as are the equivalent overloadable
methods and C API methods. See the PEP for a full discussion:
<http://python.sf.net/peps/pep-0238.html>
- Future statements are now effective in simulated interactive shells
(like IDLE). This should "just work" by magic, but read Michael
Hudson's "Future statements in simulated shells" PEP 264 for full
details: <http://python.sf.net/peps/pep-0264.html>.
- The type/class unification (PEP 252-253) was integrated into the
trunk and is not so tentative any more (the exact specification of
some features is still tentative). A lot of work has done on fixing
bugs and adding robustness and features (performance still has to
come a long way).
- Warnings about a mismatch in the Python API during extension import
now use the Python warning framework (which makes it possible to
write filters for these warnings).
- A function's __dict__ (aka func_dict) will now always be a
dictionary. It used to be possible to delete it or set it to None,
but now both actions raise TypeErrors. It is still legal to set it
to a dictionary object. Getting func.__dict__ before any attributes
have been assigned now returns an empty dictionary instead of None.
- A new command line option, -E, was added which disables the use of
all environment variables, or at least those that are specifically
significant to Python. Usually those have a name starting with
"PYTHON". This was used to fix a problem where the tests fail if
the user happens to have PYTHONHOME or PYTHONPATH pointing to an
older distribution.
Library
-------
- New class Differ and new functions ndiff() and restore() in difflib.py.
These package the algorithms used by the popular Tools/scripts/ndiff.py,
for programmatic reuse.
- New function xml.sax.saxutils.quoteattr(): Quote an XML attribute
value using the minimal quoting required for the value; more
reliable than using xml.sax.saxutils.escape() for attribute values.
- Readline completion support for cmd.Cmd was added.
- Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings.
- Added function threading.BoundedSemaphore()
- Added Ka-Ping Yee's cgitb.py module.
- The 'new' module now exposes the CO_xxx flags.
- The gc module offers the get_referents function.
New platforms
-------------
C API
-----
- Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added
which provide a cross-platform implementations for the
relatively new snprintf()/vsnprintf() C lib APIs. In contrast to
the standard sprintf() and vsprintf() C lib APIs, these versions
apply bounds checking on the used buffer which enhances protection
against buffer overruns.
- Unicode APIs now use name mangling to assure that mixing interpreters
and extensions using different Unicode widths is rendered next to
impossible. Trying to import an incompatible Unicode-aware extension
will result in an ImportError. Unicode extensions writers must make
sure to check the Unicode width compatibility in their extensions by
using at least one of the mangled Unicode APIs in the extension.
- Two new flags METH_NOARGS and METH_O are available in method definition
tables to simplify implementation of methods with no arguments and a
single untyped argument. Calling such methods is more efficient than
calling corresponding METH_VARARGS methods. METH_OLDARGS is now
deprecated.
Windows
-------
- "import module" now compiles module.pyw if it exists and nothing else
relevant is found.
What's New in Python 2.2a1?
===========================
*Release date: 18-Jul-2001*
Core
----
- TENTATIVELY, a large amount of code implementing much of what's
described in PEP 252 (Making Types Look More Like Classes) and PEP
253 (Subtyping Built-in Types) was added. This will be released
with Python 2.2a1. Documentation will be provided separately
through http://www.python.org/2.2/. The purpose of releasing this
with Python 2.2a1 is to test backwards compatibility. It is
possible, though not likely, that a decision is made not to release
this code as part of 2.2 final, if any serious backwards
incompatibilities are found during alpha testing that cannot be
repaired.
- Generators were added; this is a new way to create an iterator (see
below) using what looks like a simple function containing one or
more 'yield' statements. See PEP 255. Since this adds a new
keyword to the language, this feature must be enabled by including a
future statement: "from __future__ import generators" (see PEP 236).
Generators will become a standard feature in a future release
(probably 2.3). Without this future statement, 'yield' remains an
ordinary identifier, but a warning is issued each time it is used.
(These warnings currently don't conform to the warnings framework of
PEP 230; we intend to fix this in 2.2a2.)
- The UTF-16 codec was modified to be more RFC compliant. It will now
only remove BOM characters at the start of the string and then
only if running in native mode (UTF-16-LE and -BE won't remove a
leading BMO character).
- Strings now have a new method .decode() to complement the already
existing .encode() method. These two methods provide direct access
to the corresponding decoders and encoders of the registered codecs.
To enhance the usability of the .encode() method, the special
casing of Unicode object return values was dropped (Unicode objects
were auto-magically converted to string using the default encoding).
Both methods will now return whatever the codec in charge of the
requested encoding returns as object, e.g. Unicode codecs will
return Unicode objects when decoding is requested ("äöü".decode("latin-1")
will return u"äöü"). This enables codec writer to create codecs
for various simple to use conversions.
New codecs were added to demonstrate these new features (the .encode()
and .decode() columns indicate the type of the returned objects):
+---------+-----------+-----------+-----------------------------+
|Name | .encode() | .decode() | Description |
+=========+===========+===========+=============================+
|uu | string | string | UU codec (e.g. for email) |
+---------+-----------+-----------+-----------------------------+
|base64 | string | string | base64 codec |
+---------+-----------+-----------+-----------------------------+
|quopri | string | string | quoted-printable codec |
+---------+-----------+-----------+-----------------------------+
|zlib | string | string | zlib compression |
+---------+-----------+-----------+-----------------------------+
|hex | string | string | 2-byte hex codec |
+---------+-----------+-----------+-----------------------------+
|rot-13 | string | Unicode | ROT-13 Unicode charmap codec|
+---------+-----------+-----------+-----------------------------+
- Some operating systems now support the concept of a default Unicode
encoding for file system operations. Notably, Windows supports 'mbcs'
as the default. The Macintosh will also adopt this concept in the medium
term, although the default encoding for that platform will be other than
'mbcs'.
On operating system that support non-ASCII filenames, it is common for
functions that return filenames (such as os.listdir()) to return Python
string objects pre-encoded using the default file system encoding for
the platform. As this encoding is likely to be different from Python's
default encoding, converting this name to a Unicode object before passing
it back to the Operating System would result in a Unicode error, as Python
would attempt to use its default encoding (generally ASCII) rather than
the default encoding for the file system.
In general, this change simply removes surprises when working with
Unicode and the file system, making these operations work as you expect,
increasing the transparency of Unicode objects in this context.
See [????] for more details, including examples.
- Float (and complex) literals in source code were evaluated to full
precision only when running from a .py file; the same code loaded from a
.pyc (or .pyo) file could suffer numeric differences starting at about the
12th significant decimal digit. For example, on a machine with IEEE-754
floating arithmetic,
x = 9007199254740992.0
print long(x)
printed 9007199254740992 if run directly from .py, but 9007199254740000
if from a compiled (.pyc or .pyo) file. This was due to marshal using
str(float) instead of repr(float) when building code objects. marshal
now uses repr(float) instead, which should reproduce floats to full
machine precision (assuming the platform C float<->string I/O conversion
functions are of good quality).
This may cause floating-point results to change in some cases, and
usually for the better, but may also cause numerically unstable
algorithms to break.
- The implementation of dicts suffers fewer collisions, which has speed
benefits. However, the order in which dict entries appear in dict.keys(),
dict.values() and dict.items() may differ from previous releases for a
given dict. Nothing is defined about this order, so no program should
rely on it. Nevertheless, it's easy to write test cases that rely on the
order by accident, typically because of printing the str() or repr() of a
dict to an "expected results" file. See Lib/test/test_support.py's new
sortdict(dict) function for a simple way to display a dict in sorted
order.
- Many other small changes to dicts were made, resulting in faster
operation along the most common code paths.
- Dictionary objects now support the "in" operator: "x in dict" means
the same as dict.has_key(x).
- The update() method of dictionaries now accepts generic mapping
objects. Specifically the argument object must support the .keys()
and __getitem__() methods. This allows you to say, for example,
{}.update(UserDict())
- Iterators were added; this is a generalized way of providing values
to a for loop. See PEP 234. There's a new built-in function iter()
to return an iterator. There's a new protocol to get the next value
from an iterator using the next() method (in Python) or the
tp_iternext slot (in C). There's a new protocol to get iterators
using the __iter__() method (in Python) or the tp_iter slot (in C).
Iterating (i.e. a for loop) over a dictionary generates its keys.
Iterating over a file generates its lines.
- The following functions were generalized to work nicely with iterator
arguments::
map(), filter(), reduce(), zip()
list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API)
max(), min()
join() method of strings
extend() method of lists
'x in y' and 'x not in y' (PySequence_Contains() in C API)
operator.countOf() (PySequence_Count() in C API)
right-hand side of assignment statements with multiple targets, such as ::
x, y, z = some_iterable_object_returning_exactly_3_values
- Accessing module attributes is significantly faster (for example,
random.random or os.path or yourPythonModule.yourAttribute).
- Comparing dictionary objects via == and != is faster, and now works even
if the keys and values don't support comparisons other than ==.
- Comparing dictionaries in ways other than == and != is slower: there were
insecurities in the dict comparison implementation that could cause Python
to crash if the element comparison routines for the dict keys and/or
values mutated the dicts. Making the code bulletproof slowed it down.
- Collisions in dicts are resolved via a new approach, which can help
dramatically in bad cases. For example, looking up every key in a dict
d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x
faster now. Thanks to Christian Tismer for pointing out the cause and
the nature of an effective cure (last December! better late than never).
- repr() is much faster for large containers (dict, list, tuple).
Library
-------
- The constants ascii_letters, ascii_lowercase. and ascii_uppercase
were added to the string module. These a locale-independent
constants, unlike letters, lowercase, and uppercase. These are now
use in appropriate locations in the standard library.
- The flags used in dlopen calls can now be configured using
sys.setdlopenflags and queried using sys.getdlopenflags.
- Fredrik Lundh's xmlrpclib is now a standard library module. This
provides full client-side XML-RPC support. In addition,
Demo/xmlrpc/ contains two server frameworks (one SocketServer-based,
one asyncore-based). Thanks to Eric Raymond for the documentation.
- The xrange() object is simplified: it no longer supports slicing,
repetition, comparisons, efficient 'in' checking, the tolist()
method, or the start, stop and step attributes. See PEP 260.
- A new function fnmatch.filter to filter lists of file names was added.
- calendar.py uses month and day names based on the current locale.
- strop is now *really* obsolete (this was announced before with 1.6),
and issues DeprecationWarning when used (except for the four items
that are still imported into string.py).
- Cookie.py now sorts key+value pairs by key in output strings.
- pprint.isrecursive(object) didn't correctly identify recursive objects.
Now it does.
- pprint functions now much faster for large containers (tuple, list, dict).
- New 'q' and 'Q' format codes in the struct module, corresponding to C
types "long long" and "unsigned long long" (on Windows, __int64). In
native mode, these can be used only when the platform C compiler supports
these types (when HAVE_LONG_LONG is #define'd by the Python config
process), and then they inherit the sizes and alignments of the C types.
In standard mode, 'q' and 'Q' are supported on all platforms, and are
8-byte integral types.
- The site module installs a new built-in function 'help' that invokes
pydoc.help. It must be invoked as 'help()'; when invoked as 'help',
it displays a message reminding the user to use 'help()' or
'help(object)'.
Tests
-----
- New test_mutants.py runs dict comparisons where the key and value
comparison operators mutate the dicts randomly during comparison. This
rapidly causes Python to crash under earlier releases (not for the faint
of heart: it can also cause Win9x to freeze or reboot!).
- New test_pprint.py verifies that pprint.isrecursive() and
pprint.isreadable() return sensible results. Also verifies that simple
cases produce correct output.
C API
-----
- Removed the unused last_is_sticky argument from the internal
_PyTuple_Resize(). If this affects you, you were cheating.
What's New in Python 2.1 (final)?
=================================
We only changed a few things since the last release candidate, all in
Python library code:
- A bug in the locale module was fixed that affected locales which
define no grouping for numeric formatting.
- A few bugs in the weakref module's implementations of weak
dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed,
and the test suite was updated to check for these bugs.
- An old bug in the os.path.walk() function (introduced in Python
2.0!) was fixed: a non-existent file would cause an exception
instead of being ignored.
- Fixed a few bugs in the new symtable module found by Neil Norwitz's
PyChecker.
What's New in Python 2.1c2?
===========================
A flurry of small changes, and one showstopper fixed in the nick of
time made it necessary to release another release candidate. The list
here is the *complete* list of patches (except version updates):
Core
- Tim discovered a nasty bug in the dictionary code, caused by
PyDict_Next() calling dict_resize(), and the GC code's use of
PyDict_Next() violating an assumption in dict_items(). This was
fixed with considerable amounts of band-aid, but the net effect is a
saner and more robust implementation.
- Made a bunch of symbols static that were accidentally global.
Build and Ports
- The setup.py script didn't check for a new enough version of zlib
(1.1.3 is needed). Now it does.
- Changed "make clean" target to also remove shared libraries.
- Added a more general warning about the SGI Irix optimizer to README.
Library
- Fix a bug in urllib.basejoin("http://host", "../file.html") which
omitted the slash between host and file.html.
- The mailbox module's _Mailbox class contained a completely broken
and undocumented seek() method. Ripped it out.
- Fixed a bunch of typos in various library modules (urllib2, smtpd,
sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker.
- Fixed a few last-minute bugs in unittest.
Extensions
- Reverted the patch to the OpenSSL code in socketmodule.c to support
RAND_status() and the EGD, and the subsequent patch that tried to
fix it for pre-0.9.5 versions; the problem with the patch is that on
some systems it issues a warning whenever socket is imported, and
that's unacceptable.
Tests
- Fixed the pickle tests to work with "import test.test_pickle".
- Tweaked test_locale.py to actually run the test Windows.
- In distutils/archive_util.py, call zipfile.ZipFile() with mode "w",
not "wb" (which is not a valid mode at all).
- Fix pstats browser crashes. Import readline if it exists to make
the user interface nicer.
- Add "import thread" to the top of test modules that import the
threading module (test_asynchat and test_threadedtempfile). This
prevents test failures caused by a broken threading module resulting
from a previously caught failed import.
- Changed test_asynchat.py to set the SO_REUSEADDR option; this was
needed on some platforms (e.g. Solaris 8) when the tests are run
twice in succession.
- Skip rather than fail test_sunaudiodev if no audio device is found.
What's New in Python 2.1c1?
===========================
This list was significantly updated when 2.1c2 was released; the 2.1c1
release didn't mention most changes that were actually part of 2.1c1:
Legal
- Copyright was assigned to the Python Software Foundation (PSF) and a
PSF license (very similar to the CNRI license) was added.
- The CNRI copyright notice was updated to include 2001.
Core
- After a public outcry, assignment to __debug__ is no longer illegal;
instead, a warning is issued. It will become illegal in 2.2.
- Fixed a core dump with "%#x" % 0, and changed the semantics so that
"%#x" now always prepends "0x", even if the value is zero.
- Fixed some nits in the bytecode compiler.
- Fixed core dumps when calling certain kinds of non-functions.
- Fixed various core dumps caused by reference count bugs.
Build and Ports
- Use INSTALL_SCRIPT to install script files.
- New port: SCO Unixware 7, by Billy G. Allie.
- Updated RISCOS port.
- Updated BeOS port and notes.
- Various other porting problems resolved.
Library
- The TERMIOS and SOCKET modules are now truly obsolete and
unnecessary. Their symbols are incorporated in the termios and
socket modules.
- Fixed some 64-bit bugs in pickle, cPickle, and struct, and added
better tests for pickling.
- threading: make Condition.wait() robust against KeyboardInterrupt.
- zipfile: add support to zipfile to support opening an archive
represented by an open file rather than a file name. Fix bug where
the archive was not properly closed. Fixed a bug in this bugfix
where flush() was called for a read-only file.
- imputil: added an uninstall() method to the ImportManager.
- Canvas: fixed bugs in lower() and tkraise() methods.
- SocketServer: API change (added overridable close_request() method)
so that the TCP server can explicitly close the request.
- pstats: Eric Raymond added a simple interactive statistics browser,
invoked when the module is run as a script.
- locale: fixed a problem in format().
- webbrowser: made it work when the BROWSER environment variable has a
value like "/usr/bin/netscape". Made it auto-detect Konqueror for
KDE 2. Fixed some other nits.
- unittest: changes to allow using a different exception than
AssertionError, and added a few more function aliases. Some other
small changes.
- urllib, urllib2: fixed redirect problems and a coupleof other nits.
- asynchat: fixed a critical bug in asynchat that slipped through the
2.1b2 release. Fixed another rare bug.
- Fix some unqualified except: clauses (always a bad code example).
XML
- pyexpat: new API get_version_string().
- Fixed some minidom bugs.
Extensions
- Fixed a core dump in _weakref. Removed the weakref.mapping()
function (it adds nothing to the API).
- Rationalized the use of header files in the readline module, to make
it compile (albeit with some warnings) with the very recent readline
4.2, without breaking for earlier versions.
- Hopefully fixed a buffering problem in linuxaudiodev.
- Attempted a fix to make the OpenSSL support in the socket module
work again with pre-0.9.5 versions of OpenSSL.
Tests
- Added a test case for asynchat and asyncore.
- Removed coupling between tests where one test failing could break
another.
Tools
- Ping added an interactive help browser to pydoc, fixed some nits
in the rest of the pydoc code, and added some features to his
inspect module.
- An updated python-mode.el version 4.1 which integrates Ken
Manheimer's pdbtrack.el. This makes debugging Python code via pdb
much nicer in XEmacs and Emacs. When stepping through your program
with pdb, in either the shell window or the *Python* window, the
source file and line will be tracked by an arrow. Very cool!
- IDLE: syntax warnings in interactive mode are changed into errors.
- Some improvements to Tools/webchecker (ignore some more URL types,
follow some more links).
- Brought the Tools/compiler package up to date.
What's New in Python 2.1 beta 2?
================================
(Unlisted are many fixed bugs, more documentation, etc.)
Core language, builtins, and interpreter
- The nested scopes work (enabled by "from __future__ import
nested_scopes") is completed; in particular, the future now extends
into code executed through exec, eval() and execfile(), and into the
interactive interpreter.
- When calling a base class method (e.g. BaseClass.__init__(self)),
this is now allowed even if self is not strictly spoken a class
instance (e.g. when using metaclasses or the Don Beaudry hook).
- Slice objects are now comparable but not hashable; this prevents
dict[:] from being accepted but meaningless.
- Complex division is now calculated using less braindead algorithms.
This doesn't change semantics except it's more likely to give useful
results in extreme cases. Complex repr() now uses full precision
like float repr().
- sgmllib.py now calls handle_decl() for simple <!...> declarations.
- It is illegal to assign to the name __debug__, which is set when the
interpreter starts. It is effectively a compile-time constant.
- A warning will be issued if a global statement for a variable
follows a use or assignment of that variable.
Standard library
- unittest.py, a unit testing framework by Steve Purcell (PyUNIT,
inspired by JUnit), is now part of the standard library. You now
have a choice of two testing frameworks: unittest requires you to
write testcases as separate code, doctest gathers them from
docstrings. Both approaches have their advantages and
disadvantages.
- A new module Tix was added, which wraps the Tix extension library
for Tk. With that module, it is not necessary to statically link
Tix with _tkinter, since Tix will be loaded with Tcl's "package
require" command. See Demo/tix/.
- tzparse.py is now obsolete.
- In gzip.py, the seek() and tell() methods are removed -- they were
non-functional anyway, and it's better if callers can test for their
existence with hasattr().
Python/C API
- PyDict_Next(): it is now safe to call PyDict_SetItem() with a key
that's already in the dictionary during a PyDict_Next() iteration.
This used to fail occasionally when a dictionary resize operation
could be triggered that would rehash all the keys. All other
modifications to the dictionary are still off-limits during a
PyDict_Next() iteration!
- New extended APIs related to passing compiler variables around.
- New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass()
implement isinstance() and issubclass().
- Py_BuildValue() now has a "D" conversion to create a Python complex
number from a Py_complex C value.
- Extensions types which support weak references must now set the
field allocated for the weak reference machinery to NULL themselves;
this is done to avoid the cost of checking each object for having a
weakly referencable type in PyObject_INIT(), since most types are
not weakly referencable.
- PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for
free variables and cell variables to and from the frame's f_locals.
- Variants of several functions defined in pythonrun.h have been added
to support the nested_scopes future statement. The variants all end
in Flags and take an extra argument, a PyCompilerFlags *; examples:
PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These
variants may be removed in Python 2.2, when nested scopes are
mandatory.
Distutils
- the sdist command now writes a PKG-INFO file, as described in PEP 241,
into the release tree.
- several enhancements to the bdist_wininst command from Thomas Heller
(an uninstaller, more customization of the installer's display)
- from Jack Jansen: added Mac-specific code to generate a dialog for
users to specify the command-line (because providing a command-line with
MacPython is awkward). Jack also made various fixes for the Mac
and the Metrowerks compiler.
- added 'platforms' and 'keywords' to the set of metadata that can be
specified for a distribution.
- applied patches from Jason Tishler to make the compiler class work with
Cygwin.
What's New in Python 2.1 beta 1?
================================
Core language, builtins, and interpreter
- Following an outcry from the community about the amount of code
broken by the nested scopes feature introduced in 2.1a2, we decided
to make this feature optional, and to wait until Python 2.2 (or at
least 6 months) to make it standard. The option can be enabled on a
per-module basis by adding "from __future__ import nested_scopes" at
the beginning of a module (before any other statements, but after
comments and an optional docstring). See PEP 236 (Back to the
__future__) for a description of the __future__ statement. PEP 227
(Statically Nested Scopes) has been updated to reflect this change,
and to clarify the semantics in a number of endcases.
- The nested scopes code, when enabled, has been hardened, and most
bugs and memory leaks in it have been fixed.
- Compile-time warnings are now generated for a number of conditions
that will break or change in meaning when nested scopes are enabled:
- Using "from...import *" or "exec" without in-clause in a function
scope that also defines a lambda or nested function with one or
more free (non-local) variables. The presence of the import* or
bare exec makes it impossible for the compiler to determine the
exact set of local variables in the outer scope, which makes it
impossible to determine the bindings for free variables in the
inner scope. To avoid the warning about import *, change it into
an import of explicitly name object, or move the import* statement
to the global scope; to avoid the warning about bare exec, use
exec...in... (a good idea anyway -- there's a possibility that
bare exec will be deprecated in the future).
- Use of a global variable in a nested scope with the same name as a
local variable in a surrounding scope. This will change in
meaning with nested scopes: the name in the inner scope will
reference the variable in the outer scope rather than the global
of the same name. To avoid the warning, either rename the outer
variable, or use a global statement in the inner function.
- An optional object allocator has been included. This allocator is
optimized for Python objects and should be faster and use less memory
than the standard system allocator. It is not enabled by default
because of possible thread safety problems. The allocator is only
protected by the Python interpreter lock and it is possible that some
extension modules require a thread safe allocator. The object
allocator can be enabled by providing the "--with-pymalloc" option to
configure.
Standard library
- pyexpat now detects the expat version if expat.h defines it. A
number of additional handlers are provided, which are only available
since expat 1.95. In addition, the methods SetParamEntityParsing and
GetInputContext of Parser objects are available with 1.95.x
only. Parser objects now provide the ordered_attributes and
specified_attributes attributes. A new module expat.model was added,
which offers a number of additional constants if 1.95.x is used.
- xml.dom offers the new functions registerDOMImplementation and
getDOMImplementation.
- xml.dom.minidom offers a toprettyxml method. A number of DOM
conformance issues have been resolved. In particular, Element now
has an hasAttributes method, and the handling of namespaces was
improved.
- Ka-Ping Yee contributed two new modules: inspect.py, a module for
getting information about live Python code, and pydoc.py, a module
for interactively converting docstrings to HTML or text.
Tools/scripts/pydoc, which is now automatically installed into
<prefix>/bin, uses pydoc.py to display documentation; try running
"pydoc -h" for instructions. "pydoc -g" pops up a small GUI that
lets you browse the module docstrings using a web browser.
- New library module difflib.py, primarily packaging the SequenceMatcher
class at the heart of the popular ndiff.py file-comparison tool.
- doctest.py (a framework for verifying Python code examples in docstrings)
is now part of the std library.
Windows changes
- A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a
small GUI that lets you browse the module docstrings using your
default web browser.
- Import is now case-sensitive. PEP 235 (Import on Case-Insensitive
Platforms) is implemented. See
http://python.sourceforge.net/peps/pep-0235.html
for full details, especially the "Current Lower-Left Semantics" section.
The new Windows import rules are simpler than before:
A. If the PYTHONCASEOK environment variable exists, same as
before: silently accept the first case-insensitive match of any
kind; raise ImportError if none found.
B. Else search sys.path for the first case-sensitive match; raise
ImportError if none found.
The same rules have been implemented on other platforms with case-
insensitive but case-preserving filesystems too (including Cygwin, and
several flavors of Macintosh operating systems).
- winsound module: Under Win9x, winsound.Beep() now attempts to simulate
what it's supposed to do (and does do under NT and 2000) via direct
port manipulation. It's unknown whether this will work on all systems,
but it does work on my Win98SE systems now and was known to be useless on
all Win9x systems before.
- Build: Subproject _test (effectively) renamed to _testcapi.
New platforms
- 2.1 should compile and run out of the box under MacOS X, even using HFS+.
Thanks to Steven Majewski!
- 2.1 should compile and run out of the box on Cygwin. Thanks to Jason
Tishler!
- 2.1 contains new files and patches for RISCOS, thanks to Dietmar
Schwertberger! See RISCOS/README for more information -- it seems
that because of the bizarre filename conventions on RISCOS, no port
to that platform is easy.
What's New in Python 2.1 alpha 2?
=================================
Core language, builtins, and interpreter
- Scopes nest. If a name is used in a function or class, but is not
local, the definition in the nearest enclosing function scope will
be used. One consequence of this change is that lambda statements
could reference variables in the namespaces where the lambda is
defined. In some unusual cases, this change will break code.
In all previous version of Python, names were resolved in exactly
three namespaces -- the local namespace, the global namespace, and
the builtin namespace. According to this old definition, if a
function A is defined within a function B, the names bound in B are
not visible in A. The new rules make names bound in B visible in A,
unless A contains a name binding that hides the binding in B.
Section 4.1 of the reference manual describes the new scoping rules
in detail. The test script in Lib/test/test_scope.py demonstrates
some of the effects of the change.
The new rules will cause existing code to break if it defines nested
functions where an outer function has local variables with the same
name as globals or builtins used by the inner function. Example:
def munge(str):
def helper(x):
return str(x)
if type(str) != type(''):
str = helper(str)
return str.strip()
Under the old rules, the name str in helper() is bound to the
builtin function str(). Under the new rules, it will be bound to
the argument named str and an error will occur when helper() is
called.
- The compiler will report a SyntaxError if "from ... import *" occurs
in a function or class scope. The language reference has documented
that this case is illegal, but the compiler never checked for it.
The recent introduction of nested scope makes the meaning of this
form of name binding ambiguous. In a future release, the compiler
may allow this form when there is no possibility of ambiguity.
- repr(string) is easier to read, now using hex escapes instead of octal,
and using \t, \n and \r instead of \011, \012 and \015 (respectively):
>>> "\texample \r\n" + chr(0) + chr(255)
'\texample \r\n\x00\xff' # in 2.1
'\011example \015\012\000\377' # in 2.0
- Functions are now compared and hashed by identity, not by value, since
the func_code attribute is writable.
- Weak references (PEP 205) have been added. This involves a few
changes in the core, an extension module (_weakref), and a Python
module (weakref). The weakref module is the public interface. It
includes support for "explicit" weak references, proxy objects, and
mappings with weakly held values.
- A 'continue' statement can now appear in a try block within the body
of a loop. It is still not possible to use continue in a finally
clause.
Standard library
- mailbox.py now has a new class, PortableUnixMailbox which is
identical to UnixMailbox but uses a more portable scheme for
determining From_ separators. Also, the constructors for all the
classes in this module have a new optional `factory' argument, which
is a callable used when new message classes must be instantiated by
the next() method.
- random.py is now self-contained, and offers all the functionality of
the now-deprecated whrandom.py. See the docs for details. random.py
also supports new functions getstate() and setstate(), for saving
and restoring the internal state of the generator; and jumpahead(n),
for quickly forcing the internal state to be the same as if n calls to
random() had been made. The latter is particularly useful for multi-
threaded programs, creating one instance of the random.Random() class for
each thread, then using .jumpahead() to force each instance to use a
non-overlapping segment of the full period.
- random.py's seed() function is new. For bit-for-bit compatibility with
prior releases, use the whseed function instead. The new seed function
addresses two problems: (1) The old function couldn't produce more than
about 2**24 distinct internal states; the new one about 2**45 (the best
that can be done in the Wichmann-Hill generator). (2) The old function
sometimes produced identical internal states when passed distinct
integers, and there was no simple way to predict when that would happen;
the new one guarantees to produce distinct internal states for all
arguments in [0, 27814431486576L).
- The socket module now supports raw packets on Linux. The socket
family is AF_PACKET.
- test_capi.py is a start at running tests of the Python C API. The tests
are implemented by the new Modules/_testmodule.c.
- A new extension module, _symtable, provides provisional access to the
internal symbol table used by the Python compiler. A higher-level
interface will be added on top of _symtable in a future release.
- Removed the obsolete soundex module.
- xml.dom.minidom now uses the standard DOM exceptions. Node supports
the isSameNode method; NamedNodeMap the get method.
- xml.sax.expatreader supports the lexical handler property; it
generates comment, startCDATA, and endCDATA events.
Windows changes
- Build procedure: the zlib project is built in a different way that
ensures the zlib header files used can no longer get out of synch with
the zlib binary used. See PCbuild\readme.txt for details. Your old
zlib-related directories can be deleted; you'll need to download fresh
source for zlib and unpack it into a new directory.
- Build: New subproject _test for the benefit of test_capi.py (see above).
- Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent
interface to some Python compiler internals).
- Build: Subproject ucnhash is gone, since the code was folded into the
unicodedata subproject.
What's New in Python 2.1 alpha 1?
=================================
Core language, builtins, and interpreter
- There is a new Unicode companion to the PyObject_Str() API
called PyObject_Unicode(). It behaves in the same way as the
former, but assures that the returned value is an Unicode object
(applying the usual coercion if necessary).
- The comparison operators support "rich comparison overloading" (PEP
207). C extension types can provide a rich comparison function in
the new tp_richcompare slot in the type object. The cmp() function
and the C function PyObject_Compare() first try the new rich
comparison operators before trying the old 3-way comparison. There
is also a new C API PyObject_RichCompare() (which also falls back on
the old 3-way comparison, but does not constrain the outcome of the
rich comparison to a Boolean result).
The rich comparison function takes two objects (at least one of
which is guaranteed to have the type that provided the function) and
an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ,
Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python
object, which may be NotImplemented (in which case the tp_compare
slot function is used as a fallback, if defined).
Classes can overload individual comparison operators by defining one
or more of the methods__lt__, __le__, __eq__, __ne__, __gt__,
__ge__. There are no explicit "reflected argument" versions of
these; instead, __lt__ and __gt__ are each other's reflection,
likewise for__le__ and __ge__; __eq__ and __ne__ are their own
reflection (similar at the C level). No other implications are
made; in particular, Python does not assume that == is the Boolean
inverse of !=, or that < is the Boolean inverse of >=. This makes
it possible to define types with partial orderings.
Classes or types that want to implement (in)equality tests but not
the ordering operators (i.e. unordered types) should implement ==
and !=, and raise an error for the ordering operators.
It is possible to define types whose rich comparison results are not
Boolean; e.g. a matrix type might want to return a matrix of bits
for A < B, giving elementwise comparisons. Such types should ensure
that any interpretation of their value in a Boolean context raises
an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot
at the C level) to always raise an exception.
- Complex numbers use rich comparisons to define == and != but raise
an exception for <, <=, > and >=. Unfortunately, this also means
that cmp() of two complex numbers raises an exception when the two
numbers differ. Since it is not mathematically meaningful to compare
complex numbers except for equality, I hope that this doesn't break
too much code.
- The outcome of comparing non-numeric objects of different types is
not defined by the language, other than that it's arbitrary but
consistent (see the Reference Manual). An implementation detail changed
in 2.1a1 such that None now compares less than any other object. Code
relying on this new behavior (like code that relied on the previous
behavior) does so at its own risk.
- Functions and methods now support getting and setting arbitrarily
named attributes (PEP 232). Functions have a new __dict__
(a.k.a. func_dict) which hold the function attributes. Methods get
and set attributes on their underlying im_func. It is a TypeError
to set an attribute on a bound method.
- The xrange() object implementation has been improved so that
xrange(sys.maxint) can be used on 64-bit platforms. There's still a
limitation that in this case len(xrange(sys.maxint)) can't be
calculated, but the common idiom "for i in xrange(sys.maxint)" will
work fine as long as the index i doesn't actually reach 2**31.
(Python uses regular ints for sequence and string indices; fixing
that is much more work.)
- Two changes to from...import:
1) "from M import X" now works even if (after loading module M)
sys.modules['M'] is not a real module; it's basically a getattr()
operation with AttributeError exceptions changed into ImportError.
2) "from M import *" now looks for M.__all__ to decide which names to
import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but
filters out names starting with '_' as before. Whether or not
__all__ exists, there's no restriction on the type of M.
- File objects have a new method, xreadlines(). This is the fastest
way to iterate over all lines in a file:
for line in file.xreadlines():
...do something to line...
See the xreadlines module (mentioned below) for how to do this for
other file-like objects.
- Even if you don't use file.xreadlines(), you may expect a speedup on
line-by-line input. The file.readline() method has been optimized
quite a bit in platform-specific ways: on systems (like Linux) that
support flockfile(), getc_unlocked(), and funlockfile(), those are
used by default. On systems (like Windows) without getc_unlocked(),
a complicated (but still thread-safe) method using fgets() is used by
default.
You can force use of the fgets() method by #define'ing
USE_FGETS_IN_GETLINE at build time (it may be faster than
getc_unlocked()).
You can force fgets() not to be used by #define'ing
DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test
test_bufio.py fails -- and let us know if it does!).
- In addition, the fileinput module, while still slower than the other
methods on most platforms, has been sped up too, by using
file.readlines(sizehint).
- Support for run-time warnings has been added, including a new
command line option (-W) to specify the disposition of warnings.
See the description of the warnings module below.
- Extensive changes have been made to the coercion code. This mostly
affects extension modules (which can now implement mixed-type
numerical operators without having to use coercion), but
occasionally, in boundary cases the coercion semantics have changed
subtly. Since this was a terrible gray area of the language, this
is considered an improvement. Also note that __rcmp__ is no longer
supported -- instead of calling __rcmp__, __cmp__ is called with
reflected arguments.
- In connection with the coercion changes, a new built-in singleton
object, NotImplemented is defined. This can be returned for
operations that wish to indicate they are not implemented for a
particular combination of arguments. From C, this is
Py_NotImplemented.
- The interpreter accepts now bytecode files on the command line even
if they do not have a .pyc or .pyo extension. On Linux, after executing
import imp,sys,string
magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"")
reg = ':pyc:M::%s::%s:' % (magic, sys.executable)
open("/proc/sys/fs/binfmt_misc/register","wb").write(reg)
any byte code file can be used as an executable (i.e. as an argument
to execve(2)).
- %[xXo] formats of negative Python longs now produce a sign
character. In 1.6 and earlier, they never produced a sign,
and raised an error if the value of the long was too large
to fit in a Python int. In 2.0, they produced a sign if and
only if too large to fit in an int. This was inconsistent
across platforms (because the size of an int varies across
platforms), and inconsistent with hex() and oct(). Example:
>>> "%x" % -0x42L
'-42' # in 2.1
'ffffffbe' # in 2.0 and before, on 32-bit machines
>>> hex(-0x42L)
'-0x42L' # in all versions of Python
The behavior of %d formats for negative Python longs remains
the same as in 2.0 (although in 1.6 and before, they raised
an error if the long didn't fit in a Python int).
%u formats don't make sense for Python longs, but are allowed
and treated the same as %d in 2.1. In 2.0, a negative long
formatted via %u produced a sign if and only if too large to
fit in an int. In 1.6 and earlier, a negative long formatted
via %u raised an error if it was too big to fit in an int.
- Dictionary objects have an odd new method, popitem(). This removes
an arbitrary item from the dictionary and returns it (in the form of
a (key, value) pair). This can be useful for algorithms that use a
dictionary as a bag of "to do" items and repeatedly need to pick one
item. Such algorithms normally end up running in quadratic time;
using popitem() they can usually be made to run in linear time.
Standard library
- In the time module, the time argument to the functions strftime,
localtime, gmtime, asctime and ctime is now optional, defaulting to
the current time (in the local timezone).
- The ftplib module now defaults to passive mode, which is deemed a
more useful default given that clients are often inside firewalls
these days. Note that this could break if ftplib is used to connect
to a *server* that is inside a firewall, from outside; this is
expected to be a very rare situation. To fix that, you can call
ftp.set_pasv(0).
- The module site now treats .pth files not only for path configuration,
but also supports extensions to the initialization code: Lines starting
with import are executed.
- There's a new module, warnings, which implements a mechanism for
issuing and filtering warnings. There are some new built-in
exceptions that serve as warning categories, and a new command line
option, -W, to control warnings (e.g. -Wi ignores all warnings, -We
turns warnings into errors). warnings.warn(message[, category])
issues a warning message; this can also be called from C as
PyErr_Warn(category, message).
- A new module xreadlines was added. This exports a single factory
function, xreadlines(). The intention is that this code is the
absolutely fastest way to iterate over all lines in an open
file(-like) object:
import xreadlines
for line in xreadlines.xreadlines(file):
...do something to line...
This is equivalent to the previous the speed record holder using
file.readlines(sizehint). Note that if file is a real file object
(as opposed to a file-like object), this is equivalent:
for line in file.xreadlines():
...do something to line...
- The bisect module has new functions bisect_left, insort_left,
bisect_right and insort_right. The old names bisect and insort
are now aliases for bisect_right and insort_right. XXX_right
and XXX_left methods differ in what happens when the new element
compares equal to one or more elements already in the list: the
XXX_left methods insert to the left, the XXX_right methods to the
right. Code that doesn't care where equal elements end up should
continue to use the old, short names ("bisect" and "insort").
- The new curses.panel module wraps the panel library that forms part
of SYSV curses and ncurses. Contributed by Thomas Gellekum.
- The SocketServer module now sets the allow_reuse_address flag by
default in the TCPServer class.
- A new function, sys._getframe(), returns the stack frame pointer of
the caller. This is intended only as a building block for
higher-level mechanisms such as string interpolation.
- The pyexpat module supports a number of new handlers, which are
available only in expat 1.2. If invocation of a callback fails, it
will report an additional frame in the traceback. Parser objects
participate now in garbage collection. If expat reports an unknown
encoding, pyexpat will try to use a Python codec; that works only
for single-byte charsets. The parser type objects is exposed as
XMLParserObject.
- xml.dom now offers standard definitions for symbolic node type and
exception code constants, and a hierarchy of DOM exceptions. minidom
was adjusted to use them.
- The conformance of xml.dom.minidom to the DOM specification was
improved. It detects a number of additional error cases; the
previous/next relationship works even when the tree is modified;
Node supports the normalize() method; NamedNodeMap, DocumentType and
DOMImplementation classes were added; Element supports the
hasAttribute and hasAttributeNS methods; and Text supports the splitText
method.
Build issues
- For Unix (and Unix-compatible) builds, configuration and building of
extension modules is now greatly automated. Rather than having to
edit the Modules/Setup file to indicate which modules should be
built and where their include files and libraries are, a
distutils-based setup.py script now takes care of building most
extension modules. All extension modules built this way are built
as shared libraries. Only a few modules that must be linked
statically are still listed in the Setup file; you won't need to
edit their configuration.
- Python should now build out of the box on Cygwin. If it doesn't,
mail to Jason Tishler (jlt63 at users.sourceforge.net).
- Python now always uses its own (renamed) implementation of getopt()
-- there's too much variation among C library getopt()
implementations.
- C++ compilers are better supported; the CXX macro is always set to a
C++ compiler if one is found.
Windows changes
- select module: By default under Windows, a select() call
can specify no more than 64 sockets. Python now boosts
this Microsoft default to 512. If you need even more than
that, see the MS docs (you'll need to #define FD_SETSIZE
and recompile Python from source).
- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3
subdirectory is no more!
What's New in Python 2.0?
=========================
Below is a list of all relevant changes since release 1.6. Older
changes are in the file HISTORY. If you are making the jump directly
from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the
HISTORY file! Many important changes listed there.
Alternatively, a good overview of the changes between 1.5.2 and 2.0 is
the document "What's New in Python 2.0" by Kuchling and Moshe Zadka:
http://www.amk.ca/python/2.0/.
--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)
======================================================================
What's new in 2.0 (since release candidate 1)?
==============================================
Standard library
- The copy_reg module was modified to clarify its intended use: to
register pickle support for extension types, not for classes.
pickle() will raise a TypeError if it is passed a class.
- Fixed a bug in gettext's "normalize and expand" code that prevented
it from finding an existing .mo file.
- Restored support for HTTP/0.9 servers in httplib.
- The math module was changed to stop raising OverflowError in case of
underflow, and return 0 instead in underflow cases. Whether Python
used to raise OverflowError in case of underflow was platform-
dependent (it did when the platform math library set errno to ERANGE
on underflow).
- Fixed a bug in StringIO that occurred when the file position was not
at the end of the file and write() was called with enough data to
extend past the end of the file.
- Fixed a bug that caused Tkinter error messages to get lost on
Windows. The bug was fixed by replacing direct use of
interp->result with Tcl_GetStringResult(interp).
- Fixed bug in urllib2 that caused it to fail when it received an HTTP
redirect response.
- Several changes were made to distutils: Some debugging code was
removed from util. Fixed the installer used when an external zip
program (like WinZip) is not found; the source code for this
installer is in Misc/distutils. check_lib() was modified to behave
more like AC_CHECK_LIB by add other_libraries() as a parameter. The
test for whether installed modules are on sys.path was changed to
use both normcase() and normpath().
- Several minor bugs were fixed in the xml package (the minidom,
pulldom, expatreader, and saxutils modules).
- The regression test driver (regrtest.py) behavior when invoked with
-l changed: It now reports a count of objects that are recognized as
garbage but not freed by the garbage collector.
- The regression test for the math module was changed to test
exceptional behavior when the test is run in verbose mode. Python
cannot yet guarantee consistent exception behavior across platforms,
so the exception part of test_math is run only in verbose mode, and
may fail on your platform.
Internals
- PyOS_CheckStack() has been disabled on Win64, where it caused
test_sre to fail.
Build issues
- Changed compiler flags, so that gcc is always invoked with -Wall and
-Wstrict-prototypes. Users compiling Python with GCC should see
exactly one warning, except if they have passed configure the
--with-pydebug flag. The expected warning is for getopt() in
Modules/main.c. This warning will be fixed for Python 2.1.
- Fixed configure to add -threads argument during linking on OSF1.
Tools and other miscellany
- The compiler in Tools/compiler was updated to support the new
language features introduced in 2.0: extended print statement, list
comprehensions, and augmented assignments. The new compiler should
also be backwards compatible with Python 1.5.2; the compiler will
always generate code for the version of the interpreter it runs
under.
What's new in 2.0 release candidate 1 (since beta 2)?
=====================================================
What is release candidate 1?
We believe that release candidate 1 will fix all known bugs that we
intend to fix for the 2.0 final release. This release should be a bit
more stable than the previous betas. We would like to see even more
widespread testing before the final release, so we are producing this
release candidate. The final release will be exactly the same unless
any show-stopping (or brown bag) bugs are found by testers of the
release candidate.
All the changes since the last beta release are bug fixes or changes
to support building Python for specific platforms.
Core language, builtins, and interpreter
- A bug that caused crashes when __coerce__ was used with augmented
assignment, e.g. +=, was fixed.
- Raise ZeroDivisionError when raising zero to a negative number,
e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin
power operator and the result of math.pow(0.0, -2.0) will vary by
platform. On Linux, it raises a ValueError.
- A bug in Unicode string interpolation was fixed that occasionally
caused errors with formats including "%%". For example, the
following expression "%% %s" % u"abc" no longer raises a TypeError.
- Compilation of deeply nested expressions raises MemoryError instead
of SyntaxError, e.g. eval("[" * 50 + "]" * 50).
- In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode,
rendering them useless. They are now written in binary mode again.
Standard library
- Keyword arguments are now accepted for most pattern and match object
methods in SRE, the standard regular expression engine.
- In SRE, fixed error with negative lookahead and lookbehind that
manifested itself as a runtime error in patterns like "(?<!abc)(def)".
- Several bugs in the Unicode handling and error handling in _tkinter
were fixed.
- Fix memory management errors in Merge() and Tkapp_Call() routines.
- Several changes were made to cStringIO to make it compatible with
the file-like object interface and with StringIO. If operations are
performed on a closed object, an exception is raised. The truncate
method now accepts a position argument and readline accepts a size
argument.
- There were many changes made to the linuxaudiodev module and its
test suite; as a result, a short, unexpected audio sample should now
play when the regression test is run.
Note that this module is named poorly, because it should work
correctly on any platform that supports the Open Sound System
(OSS).
The module now raises exceptions when errors occur instead of
crashing. It also defines the AFMT_A_LAW format (logarithmic A-law
audio) and defines a getptr() method that calls the
SNDCTL_DSP_GETxPTR ioctl defined in the OSS Programmer's Guide.
- The library_version attribute, introduced in an earlier beta, was
removed because it can not be supported with early versions of the C
readline library, which provides no way to determine the version at
compile-time.
- The binascii module is now enabled on Win64.
- tokenize.py no longer suffers "recursion depth" errors when parsing
programs with very long string literals.
Internals
- Fixed several buffer overflow vulnerabilities in calculate_path(),
which is called when the interpreter starts up to determine where
the standard library is installed. These vulnerabilities affect all
previous versions of Python and can be exploited by setting very
long values for PYTHONHOME or argv[0]. The risk is greatest for a
setuid Python script, although use of the wrapper in
Misc/setuid-prog.c will eliminate the vulnerability.
- Fixed garbage collection bugs in instance creation that were
triggered when errors occurred during initialization. The solution,
applied in cPickle and in PyInstance_New(), is to call
PyObject_GC_Init() after the initialization of the object's
container attributes is complete.
- pyexpat adds definitions of PyModule_AddStringConstant and
PyModule_AddObject if the Python version is less than 2.0, which
provides compatibility with PyXML on Python 1.5.2.
- If the platform has a bogus definition for LONG_BIT (the number of
bits in a long), an error will be reported at compile time.
- Fix bugs in _PyTuple_Resize() which caused hard-to-interpret garbage
collection crashes and possibly other, unreported crashes.
- Fixed a memory leak in _PyUnicode_Fini().
Build issues
- configure now accepts a --with-suffix option that specifies the
executable suffix. This is useful for builds on Cygwin and Mac OS
X, for example.
- The mmap.PAGESIZE constant is now initialized using sysconf when
possible, which eliminates a dependency on -lucb for Reliant UNIX.
- The md5 file should now compile on all platforms.
- The select module now compiles on platforms that do not define
POLLRDNORM and related constants.
- Darwin (Mac OS X): Initial support for static builds on this
platform.
- BeOS: A number of changes were made to the build and installation
process. ar-fake now operates on a directory of object files.
dl_export.h is gone, and its macros now appear on the mwcc command
line during build on PPC BeOS.
- Platform directory in lib/python2.0 is "plat-beos5" (or
"plat-beos4", if building on BeOS 4.5), rather than "plat-beos".
- Cygwin: Support for shared libraries, Tkinter, and sockets.
- SunOS 4.1.4_JL: Fix test for directory existence in configure.
Tools and other miscellany
- Removed debugging prints from main used with freeze.
- IDLE auto-indent no longer crashes when it encounters Unicode
characters.
What's new in 2.0 beta 2 (since beta 1)?
========================================
Core language, builtins, and interpreter
- Add support for unbounded ints in %d,i,u,x,X,o formats; for example
"%d" % 2L**64 == "18446744073709551616".
- Add -h and -V command line options to print the usage message and
Python version number and exit immediately.
- eval() and exec accept Unicode objects as code parameters.
- getattr() and setattr() now also accept Unicode objects for the
attribute name, which are converted to strings using the default
encoding before lookup.
- Multiplication on string and Unicode now does proper bounds
checking; e.g. 'a' * 65536 * 65536 will raise ValueError, "repeated
string is too long."
- Better error message when continue is found in try statement in a
loop.
Standard library and extensions
- socket module: the OpenSSL code now adds support for RAND_status()
and EGD (Entropy Gathering Device).
- array: reverse() method of array now works. buffer_info() now does
argument checking; it still takes no arguments.
- asyncore/asynchat: Included most recent version from Sam Rushing.
- cgi: Accept '&' or ';' as separator characters when parsing form data.
- CGIHTTPServer: Now works on Windows (and perhaps even Mac).
- ConfigParser: When reading the file, options spelled in upper case
letters are now correctly converted to lowercase.
- copy: Copy Unicode objects atomically.
- cPickle: Fail gracefully when copy_reg can't be imported.
- cStringIO: Implemented readlines() method.
- dbm: Add get() and setdefault() methods to dbm object. Add constant
`library' to module that names the library used. Added doc strings
and method names to error messages. Uses configure to determine
which ndbm.h file to include; Berkeley DB's nbdm and GDBM's ndbm is
now available options.
- distutils: Update to version 0.9.3.
- dl: Add several dl.RTLD_ constants.
- fpectl: Now supported on FreeBSD.
- gc: Add DEBUG_SAVEALL option. When enabled all garbage objects
found by the collector will be saved in gc.garbage. This is useful
for debugging a program that creates reference cycles.
- httplib: Three changes: Restore support for set_debuglevel feature
of HTTP class. Do not close socket on zero-length response. Do not
crash when server sends invalid content-length header.
- mailbox: Mailbox class conforms better to qmail specifications.
- marshal: When reading a short, sign-extend on platforms where shorts
are bigger than 16 bits. When reading a long, repair the unportable
sign extension that was being done for 64-bit machines. (It assumed
that signed right shift sign-extends.)
- operator: Add contains(), invert(), __invert__() as aliases for
__contains__(), inv(), and __inv__() respectively.
- os: Add support for popen2() and popen3() on all platforms where
fork() exists. (popen4() is still in the works.)
- os: (Windows only:) Add startfile() function that acts like double-
clicking on a file in Explorer (or passing the file name to the
DOS "start" command).
- os.path: (Windows, DOS:) Treat trailing colon correctly in
os.path.join. os.path.join("a:", "b") yields "a:b".
- pickle: Now raises ValueError when an invalid pickle that contains
a non-string repr where a string repr was expected. This behavior
matches cPickle.
- posixfile: Remove broken __del__() method.
- py_compile: support CR+LF line terminators in source file.
- readline: Does not immediately exit when ^C is hit when readline and
threads are configured. Adds definition of rl_library_version. (The
latter addition requires GNU readline 2.2 or later.)
- rfc822: Domain literals returned by AddrlistClass method
getdomainliteral() are now properly wrapped in brackets.
- site: sys.setdefaultencoding() should only be called in case the
standard default encoding ("ascii") is changed. This saves quite a
few cycles during startup since the first call to
setdefaultencoding() will initialize the codec registry and the
encodings package.
- socket: Support for size hint in readlines() method of object returned
by makefile().
- sre: Added experimental expand() method to match objects. Does not
use buffer interface on Unicode strings. Does not hang if group id
is followed by whitespace.
- StringIO: Size hint in readlines() is now supported as documented.
- struct: Check ranges for bytes and shorts.
- urllib: Improved handling of win32 proxy settings. Fixed quote and
quote_plus functions so that the always encode a comma.
- Tkinter: Image objects are now guaranteed to have unique ids. Set
event.delta to zero if Tk version doesn't support mousewheel.
Removed some debugging prints.
- UserList: now implements __contains__().
- webbrowser: On Windows, use os.startfile() instead of os.popen(),
which works around a bug in Norton AntiVirus 2000 that leads directly
to a Blue Screen freeze.
- xml: New version detection code allows PyXML to override standard
XML package if PyXML version is greater than 0.6.1.
- xml.dom: DOM level 1 support for basic XML. Includes xml.dom.minidom
(conventional DOM), and xml.dom.pulldom, which allows building the DOM
tree only for nodes which are sufficiently interesting to a specific
application. Does not provide the HTML-specific extensions. Still
undocumented.
- xml.sax: SAX 2 support for Python, including all the handler
interfaces needed to process XML 1.0 compliant XML. Some
documentation is already available.
- pyexpat: Renamed to xml.parsers.expat since this is part of the new,
packagized XML support.
C API
- Add three new convenience functions for module initialization --
PyModule_AddObject(), PyModule_AddIntConstant(), and
PyModule_AddStringConstant().
- Cleaned up definition of NULL in C source code; all definitions were
removed and add #error to Python.h if NULL isn't defined after
#include of stdio.h.
- Py_PROTO() macros that were removed in 2.0b1 have been restored for
backwards compatibility (at the source level) with old extensions.
- A wrapper API was added for signal() and sigaction(). Instead of
either function, always use PyOS_getsig() to get a signal handler
and PyOS_setsig() to set one. A new convenience typedef
PyOS_sighandler_t is defined for the type of signal handlers.
- Add PyString_AsStringAndSize() function that provides access to the
internal data buffer and size of a string object -- or the default
encoded version of a Unicode object.
- PyString_Size() and PyString_AsString() accept Unicode objects.
- The standard header <limits.h> is now included by Python.h (if it
exists). INT_MAX and LONG_MAX will always be defined, even if
<limits.h> is not available.
- PyFloat_FromString takes a second argument, pend, that was
effectively useless. It is now officially useless but preserved for
backwards compatibility. If the pend argument is not NULL, *pend is
set to NULL.
- PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects
for the attribute name. See note on getattr() above.
- A few bug fixes to argument processing for Unicode.
PyArg_ParseTupleAndKeywords() now accepts "es#" and "es".
PyArg_Parse() special cases "s#" for Unicode objects; it returns a
pointer to the default encoded string data instead of to the raw
UTF-16.
- Py_BuildValue accepts B format (for bgen-generated code).
Internals
- On Unix, fix code for finding Python installation directory so that
it works when argv[0] is a relative path.
- Added a true unicode_internal_encode() function and fixed the
unicode_internal_decode function() to support Unicode objects directly
rather than by generating a copy of the object.
- Several of the internal Unicode tables are much smaller now, and
the source code should be much friendlier to weaker compilers.
- In the garbage collector: Fixed bug in collection of tuples. Fixed
bug that caused some instances to be removed from the container set
while they were still live. Fixed parsing in gc.set_debug() for
platforms where sizeof(long) > sizeof(int).
- Fixed refcount problem in instance deallocation that only occurred
when Py_REF_DEBUG was defined and Py_TRACE_REFS was not.
- On Windows, getpythonregpath is now protected against null data in
registry key.
- On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race
condition.
Build and platform-specific issues
- Better support of GNU Pth via --with-pth configure option.
- Python/C API now properly exposed to dynamically-loaded extension
modules on Reliant UNIX.
- Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c:
Don't define MS_SYNC to be zero when it is undefined. Added missing
prototypes in posixmodule.c.
- Improved support for HP-UX build. Threads should now be correctly
configured (on HP-UX 10.20 and 11.00).
- Fix largefile support on older NetBSD systems and OpenBSD by adding
define for TELL64.
Tools and other miscellany
- ftpmirror: Call to main() is wrapped in if __name__ == "__main__".
- freeze: The modulefinder now works with 2.0 opcodes.
- IDLE:
Move hackery of sys.argv until after the Tk instance has been
created, which allows the application-specific Tkinter
initialization to be executed if present; also pass an explicit
className parameter to the Tk() constructor.
What's new in 2.0 beta 1?
=========================
Source Incompatibilities
------------------------
None. Note that 1.6 introduced several incompatibilities with 1.5.2,
such as single-argument append(), connect() and bind(), and changes to
str(long) and repr(float).
Binary Incompatibilities
------------------------
- Third party extensions built for Python 1.5.x or 1.6 cannot be used
with Python 2.0; these extensions will have to be rebuilt for Python
2.0.
- On Windows, attempting to import a third party extension built for
Python 1.5.x or 1.6 results in an immediate crash; there's not much we
can do about this. Check your PYTHONPATH environment variable!
- Python bytecode files (*.pyc and *.pyo) are not compatible between
releases.
Overview of Changes Since 1.6
-----------------------------
There are many new modules (including brand new XML support through
the xml package, and i18n support through the gettext module); a list
of all new modules is included below. Lots of bugs have been fixed.
The process for making major new changes to the language has changed
since Python 1.6. Enhancements must now be documented by a Python
Enhancement Proposal (PEP) before they can be accepted.
There are several important syntax enhancements, described in more
detail below:
- Augmented assignment, e.g. x += 1
- List comprehensions, e.g. [x**2 for x in range(10)]
- Extended import statement, e.g. import Module as Name
- Extended print statement, e.g. print >> file, "Hello"
Other important changes:
- Optional collection of cyclical garbage
Python Enhancement Proposal (PEP)
---------------------------------
PEP stands for Python Enhancement Proposal. A PEP is a design
document providing information to the Python community, or describing
a new feature for Python. The PEP should provide a concise technical
specification of the feature and a rationale for the feature.
We intend PEPs to be the primary mechanisms for proposing new
features, for collecting community input on an issue, and for
documenting the design decisions that have gone into Python. The PEP
author is responsible for building consensus within the community and
documenting dissenting opinions.
The PEPs are available at http://python.sourceforge.net/peps/.
Augmented Assignment
--------------------
This must have been the most-requested feature of the past years!
Eleven new assignment operators were added:
+= -= *= /= %= **= <<= >>= &= ^= |=
For example,
A += B
is similar to
A = A + B
except that A is evaluated only once (relevant when A is something
like dict[index].attr).
However, if A is a mutable object, A may be modified in place. Thus,
if A is a number or a string, A += B has the same effect as A = A+B
(except A is only evaluated once); but if a is a list, A += B has the
same effect as A.extend(B)!
Classes and built-in object types can override the new operators in
order to implement the in-place behavior; the not-in-place behavior is
used automatically as a fallback when an object doesn't implement the
in-place behavior. For classes, the method name is derived from the
method name for the corresponding not-in-place operator by inserting
an 'i' in front of the name, e.g. __iadd__ implements in-place
__add__.
Augmented assignment was implemented by Thomas Wouters.
List Comprehensions
-------------------
This is a flexible new notation for lists whose elements are computed
from another list (or lists). The simplest form is:
[<expression> for <variable> in <sequence>]
For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9].
This is more efficient than a for loop with a list.append() call.
You can also add a condition:
[<expression> for <variable> in <sequence> if <condition>]
For example, [w for w in words if w == w.lower()] would yield the list
of words that contain no uppercase characters. This is more efficient
than a for loop with an if statement and a list.append() call.
You can also have nested for loops and more than one 'if' clause. For
example, here's a function that flattens a sequence of sequences::
def flatten(seq):
return [x for subseq in seq for x in subseq]
flatten([[0], [1,2,3], [4,5], [6,7,8,9], []])
This prints
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
List comprehensions originated as a patch set from Greg Ewing; Skip
Montanaro and Thomas Wouters also contributed. Described by PEP 202.
Extended Import Statement
-------------------------
Many people have asked for a way to import a module under a different
name. This can be accomplished like this:
import foo
bar = foo
del foo
but this common idiom gets old quickly. A simple extension of the
import statement now allows this to be written as follows:
import foo as bar
There's also a variant for 'from ... import':
from foo import bar as spam
This also works with packages; e.g. you can write this:
import test.regrtest as regrtest
Note that 'as' is not a new keyword -- it is recognized only in this
context (this is only possible because the syntax for the import
statement doesn't involve expressions).
Implemented by Thomas Wouters. Described by PEP 221.
Extended Print Statement
------------------------
Easily the most controversial new feature, this extension to the print
statement adds an option to make the output go to a different file
than the default sys.stdout.
For example, to write an error message to sys.stderr, you can now
write:
print >> sys.stderr, "Error: bad dog!"
As a special feature, if the expression used to indicate the file
evaluates to None, the current value of sys.stdout is used. Thus:
print >> None, "Hello world"
is equivalent to
print "Hello world"
Design and implementation by Barry Warsaw. Described by PEP 214.
Optional Collection of Cyclical Garbage
---------------------------------------
Python is now equipped with a garbage collector that can hunt down
cyclical references between Python objects. It's no replacement for
reference counting; in fact, it depends on the reference counts being
correct, and decides that a set of objects belong to a cycle if all
their reference counts can be accounted for from their references to
each other. This devious scheme was first proposed by Eric Tiedemann,
and brought to implementation by Neil Schemenauer.
There's a module "gc" that lets you control some parameters of the
garbage collection. There's also an option to the configure script
that lets you enable or disable the garbage collection. In 2.0b1,
it's on by default, so that we (hopefully) can collect decent user
experience with this new feature. There are some questions about its
performance. If it proves to be too much of a problem, we'll turn it
off by default in the final 2.0 release.
Smaller Changes
---------------
A new function zip() was added. zip(seq1, seq2, ...) is equivalent to
map(None, seq1, seq2, ...) when the sequences have the same length;
i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When
the lists are not all the same length, the shortest list wins:
zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201.
sys.version_info is a tuple (major, minor, micro, level, serial).
Dictionaries have an odd new method, setdefault(key, default).
dict.setdefault(key, default) returns dict[key] if it exists; if not,
it sets dict[key] to default and returns that value. Thus:
dict.setdefault(key, []).append(item)
does the same work as this common idiom:
if not dict.has_key(key):
dict[key] = []
dict[key].append(item)
There are two new variants of SyntaxError that are raised for
indentation-related errors: IndentationError and TabError.
Changed \x to consume exactly two hex digits; see PEP 223. Added \U
escape that consumes exactly eight hex digits.
The limits on the size of expressions and file in Python source code
have been raised from 2**16 to 2**32. Previous versions of Python
were limited because the maximum argument size the Python VM accepted
was 2**16. This limited the size of object constructor expressions,
e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This
limit was raised thanks to a patch by Charles Waldman that effectively
fixes the problem. It is now much more likely that you will be
limited by available memory than by an arbitrary limit in Python.
The interpreter's maximum recursion depth can be modified by Python
programs using sys.getrecursionlimit and sys.setrecursionlimit. This
limit is the maximum number of recursive calls that can be made by
Python code. The limit exists to prevent infinite recursion from
overflowing the C stack and causing a core dump. The default value is
1000. The maximum safe value for a particular platform can be found
by running Misc/find_recursionlimit.py.
New Modules and Packages
------------------------
atexit - for registering functions to be called when Python exits.
imputil - Greg Stein's alternative API for writing custom import
hooks.
pyexpat - an interface to the Expat XML parser, contributed by Paul
Prescod.
xml - a new package with XML support code organized (so far) in three
subpackages: xml.dom, xml.sax, and xml.parsers. Describing these
would fill a volume. There's a special feature whereby a
user-installed package named _xmlplus overrides the standard
xmlpackage; this is intended to give the XML SIG a hook to distribute
backwards-compatible updates to the standard xml package.
webbrowser - a platform-independent API to launch a web browser.
Changed Modules
---------------
array -- new methods for array objects: count, extend, index, pop, and
remove
binascii -- new functions b2a_hex and a2b_hex that convert between
binary data and its hex representation
calendar -- Many new functions that support features including control
over which day of the week is the first day, returning strings instead
of printing them. Also new symbolic constants for days of week,
e.g. MONDAY, ..., SUNDAY.
cgi -- FieldStorage objects have a getvalue method that works like a
dictionary's get method and returns the value attribute of the object.
ConfigParser -- The parser object has new methods has_option,
remove_section, remove_option, set, and write. They allow the module
to be used for writing config files as well as reading them.
ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now
optionally support the RFC 959 REST command.
gzip -- readline and readlines now accept optional size arguments
httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See
the module doc strings for details.
locale -- implement getdefaultlocale for Win32 and Macintosh
marshal -- no longer dumps core when marshaling deeply nested or
recursive data structures
os -- new functions isatty, seteuid, setegid, setreuid, setregid
os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3
support under Unix.
os/pty -- support for openpty and forkpty
os.path -- fix semantics of os.path.commonprefix
smtplib -- support for sending very long messages
socket -- new function getfqdn()
readline -- new functions to read, write and truncate history files.
The readline section of the library reference manual contains an
example.
select -- add interface to poll system call
shutil -- new copyfileobj function
SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the
HTTP server.
Tkinter -- optimization of function flatten
urllib -- scans environment variables for proxy configuration,
e.g. http_proxy.
whichdb -- recognizes dumbdbm format
Obsolete Modules
----------------
None. However note that 1.6 made a whole slew of modules obsolete:
stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail,
poly, zmod, strop, util, whatsound.
Changed, New, Obsolete Tools
----------------------------
None.
C-level Changes
---------------
Several cleanup jobs were carried out throughout the source code.
All C code was converted to ANSI C; we got rid of all uses of the
Py_PROTO() macro, which makes the header files a lot more readable.
Most of the portability hacks were moved to a new header file,
pyport.h; several other new header files were added and some old
header files were removed, in an attempt to create a more rational set
of header files. (Few of these ever need to be included explicitly;
they are all included by Python.h.)
Trent Mick ensured portability to 64-bit platforms, under both Linux
and Win64, especially for the new Intel Itanium processor. Mick also
added large file support for Linux64 and Win64.
The C APIs to return an object's size have been update to consistently
use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In
previous versions, the abstract interfaces used PyXXX_Length and the
concrete interfaces used PyXXX_Size. The old names,
e.g. PyObject_Length, are still available for backwards compatibility
at the API level, but are deprecated.
The PyOS_CheckStack function has been implemented on Windows by
Fredrik Lundh. It prevents Python from failing with a stack overflow
on Windows.
The GC changes resulted in creation of two new slots on object,
tp_traverse and tp_clear. The augmented assignment changes result in
the creation of a new slot for each in-place operator.
The GC API creates new requirements for container types implemented in
C extension modules. See Include/objimpl.h for details.
PyErr_Format has been updated to automatically calculate the size of
the buffer needed to hold the formatted result string. This change
prevents crashes caused by programmer error.
New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable.
PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions
that are the same as their non-Ex counterparts except they take an
extra flag argument that tells them to close the file when done.
XXX There were other API changes that should be fleshed out here.
Windows Changes
---------------
New popen2/popen3/peopen4 in os module (see Changed Modules above).
os.popen is much more usable on Windows 95 and 98. See Microsoft
Knowledge Base article Q150956. The Win9x workaround described there
is implemented by the new w9xpopen.exe helper in the root of your
Python installation. Note that Python uses this internally; it is not
a standalone program.
Administrator privileges are no longer required to install Python
on Windows NT or Windows 2000. If you have administrator privileges,
Python's registry info will be written under HKEY_LOCAL_MACHINE.
Otherwise the installer backs off to writing Python's registry info
under HKEY_CURRENT_USER. The latter is sufficient for all "normal"
uses of Python, but will prevent some advanced uses from working
(for example, running a Python script as an NT service, or possibly
from CGI).
[This was new in 1.6] The installer no longer runs a separate Tcl/Tk
installer; instead, it installs the needed Tcl/Tk files directly in the
Python directory. If you already have a Tcl/Tk installation, this
wastes some disk space (about 4 Megs) but avoids problems with
conflicting Tcl/Tk installations, and makes it much easier for Python
to ensure that Tcl/Tk can find all its files.
[This was new in 1.6] The Windows installer now installs by default in
\Python20\ on the default volume, instead of \Program Files\Python-2.0\.
Updates to the changes between 1.5.2 and 1.6
--------------------------------------------
The 1.6 NEWS file can't be changed after the release is done, so here
is some late-breaking news:
New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(),
and changes to getlocale() and setlocale().
The new module is now enabled per default.
It is not true that the encodings codecs cannot be used for normal
strings: the string.encode() (which is also present on 8-bit strings
!) allows using them for 8-bit strings too, e.g. to convert files from
cp1252 (Windows) to latin-1 or vice-versa.
Japanese codecs are available from Tamito KAJIYAMA:
http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/
======================================================================
=======================================
==> Release 1.6 (September 5, 2000) <==
=======================================
What's new in release 1.6?
==========================
Below is a list of all relevant changes since release 1.5.2.
Source Incompatibilities
------------------------
Several small incompatible library changes may trip you up:
- The append() method for lists can no longer be invoked with more
than one argument. This used to append a single tuple made out of
all arguments, but was undocumented. To append a tuple, use
e.g. l.append((a, b, c)).
- The connect(), connect_ex() and bind() methods for sockets require
exactly one argument. Previously, you could call s.connect(host,
port), but this was undocumented. You must now write
s.connect((host, port)).
- The str() and repr() functions are now different more often. For
long integers, str() no longer appends a 'L'. Thus, str(1L) == '1',
which used to be '1L'; repr(1L) is unchanged and still returns '1L'.
For floats, repr() now gives 17 digits of precision, to ensure no
precision is lost (on all current hardware).
- The -X option is gone. Built-in exceptions are now always
classes. Many more library modules also have been converted to
class-based exceptions.
Binary Incompatibilities
------------------------
- Third party extensions built for Python 1.5.x cannot be used with
Python 1.6; these extensions will have to be rebuilt for Python 1.6.
- On Windows, attempting to import a third party extension built for
Python 1.5.x results in an immediate crash; there's not much we can do
about this. Check your PYTHONPATH environment variable!
Overview of Changes since 1.5.2
-------------------------------
For this overview, I have borrowed from the document "What's New in
Python 2.0" by Andrew Kuchling and Moshe Zadka:
http://www.amk.ca/python/2.0/ .
There are lots of new modules and lots of bugs have been fixed. A
list of all new modules is included below.
Probably the most pervasive change is the addition of Unicode support.
We've added a new fundamental datatype, the Unicode string, a new
build-in function unicode(), an numerous C APIs to deal with Unicode
and encodings. See the file Misc/unicode.txt for details, or
http://starship.python.net/crew/lemburg/unicode-proposal.txt.
Two other big changes, related to the Unicode support, are the
addition of string methods and (yet another) new regular expression
engine.
- String methods mean that you can now say s.lower() etc. instead of
importing the string module and saying string.lower(s) etc. One
peculiarity is that the equivalent of string.join(sequence,
delimiter) is delimiter.join(sequence). Use " ".join(sequence) for
the effect of string.join(sequence); to make this more readable, try
space=" " first. Note that the maxsplit argument defaults in
split() and replace() have changed from 0 to -1.
- The new regular expression engine, SRE by Fredrik Lundh, is fully
backwards compatible with the old engine, and is in fact invoked
using the same interface (the "re" module). You can explicitly
invoke the old engine by import pre, or the SRE engine by importing
sre. SRE is faster than pre, and supports Unicode (which was the
main reason to put effort in yet another new regular expression
engine -- this is at least the fourth!).
Other Changes
-------------
Other changes that won't break code but are nice to know about:
Deleting objects is now safe even for deeply nested data structures.
Long/int unifications: long integers can be used in seek() calls, as
slice indexes.
String formatting (s % args) has a new formatting option, '%r', which
acts like '%s' but inserts repr(arg) instead of str(arg). (Not yet in
alpha 1.)
Greg Ward's "distutils" package is included: this will make
installing, building and distributing third party packages much
simpler.
There's now special syntax that you can use instead of the apply()
function. f(*args, **kwds) is equivalent to apply(f, args, kwds).
You can also use variations f(a1, a2, *args, **kwds) and you can leave
one or the other out: f(*args), f(**kwds).
The built-ins int() and long() take an optional second argument to
indicate the conversion base -- of course only if the first argument
is a string. This makes string.atoi() and string.atol() obsolete.
(string.atof() was already obsolete).
When a local variable is known to the compiler but undefined when
used, a new exception UnboundLocalError is raised. This is a class
derived from NameError so code catching NameError should still work.
The purpose is to provide better diagnostics in the following example:
x = 1
def f():
print x
x = x+1
This used to raise a NameError on the print statement, which confused
even experienced Python programmers (especially if there are several
hundreds of lines of code between the reference and the assignment to
x :-).
You can now override the 'in' operator by defining a __contains__
method. Note that it has its arguments backwards: x in a causes
a.__contains__(x) to be called. That's why the name isn't __in__.
The exception AttributeError will have a more friendly error message,
e.g.: <code>'Spam' instance has no attribute 'eggs'</code>. This may
<b>break code</b> that expects the message to be exactly the attribute
name.
New Modules in 1.6
------------------
UserString - base class for deriving from the string type.
distutils - tools for distributing Python modules.
robotparser - parse a robots.txt file, for writing web spiders.
(Moved from Tools/webchecker/.)
linuxaudiodev - audio for Linux.
mmap - treat a file as a memory buffer. (Windows and Unix.)
sre - regular expressions (fast, supports unicode). Currently, this
code is very rough. Eventually, the re module will be reimplemented
using sre (without changes to the re API).
filecmp - supersedes the old cmp.py and dircmp.py modules.
tabnanny - check Python sources for tab-width dependance. (Moved from
Tools/scripts/.)
urllib2 - new and improved but incompatible version of urllib (still
experimental).
zipfile - read and write zip archives.
codecs - support for Unicode encoders/decoders.
unicodedata - provides access to the Unicode 3.0 database.
_winreg - Windows registry access.
encodings - package which provides a large set of standard codecs --
currently only for the new Unicode support. It has a drop-in extension
mechanism which allows you to add new codecs by simply copying them
into the encodings package directory. Asian codec support will
probably be made available as separate distribution package built upon
this technique and the new distutils package.
Changed Modules
---------------
readline, ConfigParser, cgi, calendar, posix, readline, xmllib, aifc,
chunk, wave, random, shelve, nntplib - minor enhancements.
socket, httplib, urllib - optional OpenSSL support (Unix only).
_tkinter - support for 8.0 up to 8.3. Support for versions older than
8.0 has been dropped.
string - most of this module is deprecated now that strings have
methods. This no longer uses the built-in strop module, but takes
advantage of the new string methods to provide transparent support for
both Unicode and ordinary strings.
Changes on Windows
------------------
The installer no longer runs a separate Tcl/Tk installer; instead, it
installs the needed Tcl/Tk files directly in the Python directory. If
you already have a Tcl/Tk installation, this wastes some disk space
(about 4 Megs) but avoids problems with conflincting Tcl/Tk
installations, and makes it much easier for Python to ensure that
Tcl/Tk can find all its files. Note: the alpha installers don't
include the documentation.
The Windows installer now installs by default in \Python16\ on the
default volume, instead of \Program Files\Python-1.6\.
Changed Tools
-------------
IDLE - complete overhaul. See the <a href="../idle/">IDLE home
page</a> for more information. (Python 1.6 alpha 1 will come with
IDLE 0.6.)
Tools/i18n/pygettext.py - Python equivalent of xgettext(1). A message
text extraction tool used for internationalizing applications written
in Python.
Obsolete Modules
----------------
stdwin and everything that uses it. (Get Python 1.5.2 if you need
it. :-)
soundex. (Skip Montanaro has a version in Python but it won't be
included in the Python release.)
cmp, cmpcache, dircmp. (Replaced by filecmp.)
dump. (Use pickle.)
find. (Easily coded using os.walk().)
grep. (Not very useful as a library module.)
packmail. (No longer has any use.)
poly, zmod. (These were poor examples at best.)
strop. (No longer needed by the string module.)
util. (This functionality was long ago built in elsewhere).
whatsound. (Use sndhdr.)
Detailed Changes from 1.6b1 to 1.6
----------------------------------
- Slight changes to the CNRI license. A copyright notice has been
added; the requirement to indicate the nature of modifications now
applies when making a derivative work available "to others" instead of
just "to the public"; the version and date are updated. The new
license has a new handle.
- Added the Tools/compiler package. This is a project led by Jeremy
Hylton to write the Python bytecode generator in Python.
- The function math.rint() is removed.
- In Python.h, "#define _GNU_SOURCE 1" was added.
- Version 0.9.1 of Greg Ward's distutils is included (instead of
version 0.9).
- A new version of SRE is included. It is more stable, and more
compatible with the old RE module. Non-matching ranges are indicated
by -1, not None. (The documentation said None, but the PRE
implementation used -1; changing to None would break existing code.)
- The winreg module has been renamed to _winreg. (There are plans for
a higher-level API called winreg, but this has not yet materialized in
a form that is acceptable to the experts.)
- The _locale module is enabled by default.
- Fixed the configuration line for the _curses module.
- A few crashes have been fixed, notably <file>.writelines() with a
list containing non-string objects would crash, and there were
situations where a lost SyntaxError could dump core.
- The <list>.extend() method now accepts an arbitrary sequence
argument.
- If __str__() or __repr__() returns a Unicode object, this is
converted to an 8-bit string.
- Unicode string comparisons is no longer aware of UTF-16
encoding peculiarities; it's a straight 16-bit compare.
- The Windows installer now installs the LICENSE file and no longer
registers the Python DLL version in the registry (this is no longer
needed). It now uses Tcl/Tk 8.3.2.
- A few portability problems have been fixed, in particular a
compilation error involving socklen_t.
- The PC configuration is slightly friendlier to non-Microsoft
compilers.
======================================================================
======================================
==> Release 1.5.2 (April 13, 1999) <==
======================================
From 1.5.2c1 to 1.5.2 (final)
=============================
Tue Apr 13 15:44:49 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* PCbuild/python15.wse: Bump version to 1.5.2 (final)
* PCbuild/python15.dsp: Added shamodule.c
* PC/config.c: Added sha module!
* README, Include/patchlevel.h: Prepare for final release.
* Misc/ACKS:
More (Cameron Laird is honorary; the others are 1.5.2c1 testers).
* Python/thread_solaris.h:
While I can't really test this thoroughly, Pat Knight and the Solaris
man pages suggest that the proper thing to do is to add THR_NEW_LWP to
the flags on thr_create(), and that there really isn't a downside, so
I'll do that.
* Misc/ACKS:
Bunch of new names who helped iron out the last wrinkles of 1.5.2.
* PC/python_nt.rc:
Bump the myusterious M$ version number from 1,5,2,1 to 1,5,2,3.
(I can't even display this on NT, maybe Win/98 can?)
* Lib/pstats.py:
Fix mysterious references to jprofile that were in the source since
its creation. I'm assuming these were once valid references to "Jim
Roskind's profile"...
* Lib/Attic/threading_api.py:
Removed; since long subsumed in Doc/lib/libthreading.tex
* Modules/socketmodule.c:
Put back __osf__ support for gethostbyname_r(); the real bug was that
it was being used even without threads. This of course might be an
all-platform problem so now we only use the _r variant when we are
using threads.
Mon Apr 12 22:51:20 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Modules/cPickle.c:
Fix accidentally reversed NULL test in load_mark(). Suggested by
Tamito Kajiyama. (This caused a bug only on platforms where malloc(0)
returns NULL.)
* README:
Add note about popen2 problem on Linux noticed by Pablo Bleyer.
* README: Add note about -D_REENTRANT for HP-UX 10.20.
* Modules/Makefile.pre.in: 'clean' target should remove hassignal.
* PC/Attic/vc40.mak, PC/readme.txt:
Remove all VC++ info (except VC 1.5) from readme.txt;
remove the VC++ 4.0 project file; remove the unused _tkinter extern defs.
* README: Clarify PC build instructions (point to PCbuild).
* Modules/zlibmodule.c: Cast added by Jack Jansen (for Mac port).
* Lib/plat-sunos5/CDIO.py, Lib/plat-linux2/CDROM.py:
Forgot to add this file. CDROM device parameters.
* Lib/gzip.py: Two different changes.
1. Jack Jansen reports that on the Mac, the time may be negative, and
solves this by adding a write32u() function that writes an unsigned
long.
2. On 64-bit platforms the CRC comparison fails; I've fixed this by
casting both values to be compared to "unsigned long" i.e. modulo
0x100000000L.
Sat Apr 10 18:42:02 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* PC/Attic/_tkinter.def: No longer needed.
* Misc/ACKS: Correct missed character in Andrew Dalke's name.
* README: Add DEC Ultrix notes (from Donn Cave's email).
* configure: The usual
* configure.in:
Quote a bunch of shell variables used in test, related to long-long.
* Objects/fileobject.c, Modules/shamodule.c, Modules/regexpr.c:
casts for picky compilers.
* Modules/socketmodule.c:
3-arg gethostbyname_r doesn't really work on OSF/1.
* PC/vc15_w31/_.c, PC/vc15_lib/_.c, Tools/pynche/__init__.py:
Avoid totally empty files.
Fri Apr 9 14:56:35 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Tools/scripts/fixps.py: Use re instead of regex.
Don't rewrite the file in place.
(Reported by Andy Dustman.)
* Lib/netrc.py, Lib/shlex.py: Get rid of #! line
Thu Apr 8 23:13:37 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* PCbuild/python15.wse: Use the Tcl 8.0.5 installer.
Add a variable %_TCL_% that makes it easier to switch to a different version.
======================================================================
From 1.5.2b2 to 1.5.2c1
=======================
Thu Apr 8 23:13:37 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* PCbuild/python15.wse:
Release 1.5.2c1. Add IDLE and Uninstall to program group.
Don't distribute zlib.dll. Tweak some comments.
* PCbuild/zlib.dsp: Now using static zlib 1.1.3
* Lib/dos-8x3/userdict.py, Lib/dos-8x3/userlist.py, Lib/dos-8x3/test_zli.py, Lib/dos-8x3/test_use.py, Lib/dos-8x3/test_pop.py, Lib/dos-8x3/test_pic.py, Lib/dos-8x3/test_ntp.py, Lib/dos-8x3/test_gzi.py, Lib/dos-8x3/test_fcn.py, Lib/dos-8x3/test_cpi.py, Lib/dos-8x3/test_bsd.py, Lib/dos-8x3/posixfil.py, Lib/dos-8x3/mimetype.py, Lib/dos-8x3/nturl2pa.py, Lib/dos-8x3/compilea.py, Lib/dos-8x3/exceptio.py, Lib/dos-8x3/basehttp.py:
The usual
* Include/patchlevel.h: Release 1.5.2c1
* README: Release 1.5.2c1.
* Misc/NEWS: News for the 1.5.2c1 release.
* Lib/test/test_strftime.py:
On Windows, we suddenly find, strftime() may return "" for an
unsupported format string. (I guess this is because the logic for
deciding whether to reallocate the buffer or not has been improved.)
This caused the test code to crash on result[0]. Fix this by assuming
an empty result also means the format is not supported.
* Demo/tkinter/matt/window-creation-w-location.py:
This demo imported some private code from Matt. Make it cripple along.
* Lib/lib-tk/Tkinter.py:
Delete an accidentally checked-in feature that actually broke more
than was worth it: when deleting a canvas item, it would try to
automatically delete the bindings for that item. Since there's
nothing that says you can't reuse the tag and still have the bindings,
this is not correct. Also, it broke at least one demo
(Demo/tkinter/matt/rubber-band-box-demo-1.py).
* Python/thread_wince.h: Win/CE thread support by Mark Hammond.
Wed Apr 7 20:23:17 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Modules/zlibmodule.c:
Patch by Andrew Kuchling to unflush() (flush() for deflating).
Without this, if inflate() returned Z_BUF_ERROR asking for more output
space, we would report the error; now, we increase the buffer size and
try again, just as for Z_OK.
* Lib/test/test_gzip.py: Use binary mode for all gzip files we open.
* Tools/idle/ChangeLog: New change log.
* Tools/idle/README.txt, Tools/idle/NEWS.txt: New version.
* Python/pythonrun.c:
Alas, get rid of the Win specific hack to ask the user to press Return
before exiting when an error happened. This didn't work right when
Python is invoked from a daemon.
* Tools/idle/idlever.py: Version bump awaiting impending new release.
(Not much has changed :-( )
* Lib/lib-tk/Tkinter.py:
lower, tkraise/lift hide Misc.lower, Misc.tkraise/lift,
so the preferred name for them is tag_lower, tag_raise
(similar to tag_bind, and similar to the Text widget);
unfortunately can't delete the old ones yet (maybe in 1.6)
* Python/thread.c, Python/strtod.c, Python/mystrtoul.c, Python/import.c, Python/ceval.c:
Changes by Mark Hammond for Windows CE. Mostly of the form
#ifdef DONT_HAVE_header_H ... #endif around #include <header.h>.
* Python/bltinmodule.c:
Remove unused variable from complex_from_string() code.
* Include/patchlevel.h:
Add the possibility of a gamma release (release candidate).
Add '+' to string version number to indicate we're beyond b2 now.
* Modules/posixmodule.c: Add extern decl for fsync() for SunOS 4.x.
* Lib/smtplib.py: Changes by Per Cederquist and The Dragon.
Per writes:
"""
The application where Signum Support uses smtplib needs to be able to
report good error messages to the user when sending email fails. To
help in diagnosing problems it is useful to be able to report the
entire message sent by the server, not only the SMTP error code of the
offending command.
A lot of the functions in sendmail.py unfortunately discards the
message, leaving only the code. The enclosed patch fixes that
problem.
The enclosed patch also introduces a base class for exceptions that
include an SMTP error code and error message, and make the code and
message available on separate attributes, so that surrounding code can
deal with them in whatever way it sees fit. I've also added some
documentation to the exception classes.
The constructor will now raise an exception if it cannot connect to
the SMTP server.
The data() method will raise an SMTPDataError if it doesn't receive
the expected 354 code in the middle of the exchange.
According to section 5.2.10 of RFC 1123 a smtp client must accept "any
text, including no text at all" after the error code. If the response
of a HELO command contains no text self.helo_resp will be set to the
empty string (""). The patch fixes the test in the sendmail() method
so that helo_resp is tested against None; if it has the empty string
as value the sendmail() method would invoke the helo() method again.
The code no longer accepts a -1 reply from the ehlo() method in
sendmail().
[Text about removing SMTPRecipientsRefused deleted --GvR]
"""
and also:
"""
smtplib.py appends an extra blank line to the outgoing mail if the
`msg' argument to the sendmail method already contains a trailing
newline. This patch should fix the problem.
"""
The Dragon writes:
"""
Mostly I just re-added the SMTPRecipientsRefused exception
(the exeption object now has the appropriate info in it ) [Per had
removed this in his patch --GvR] and tweaked the behavior of the
sendmail method whence it throws the newly added SMTPHeloException (it
was closing the connection, which it shouldn't. whatever catches the
exception should do that. )
I pondered the change of the return values to tuples all around,
and after some thinking I decided that regularizing the return values was
too much of the Right Thing (tm) to not do.
My one concern is that code expecting an integer & getting a tuple
may fail silently.
(i.e. if it's doing :
x.somemethod() >= 400:
expecting an integer, the expression will always be true if it gets a
tuple instead. )
However, most smtplib code I've seen only really uses the
sendmail() method, so this wouldn't bother it. Usually code I've seen
that calls the other methods usually only calls helo() and ehlo() for
doing ESMTP, a feature which was not in the smtplib included with 1.5.1,
and thus I would think not much code uses it yet.
"""
Tue Apr 6 19:38:18 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/test/test_ntpath.py:
Fix the tests now that splitdrive() no longer treats UNC paths special.
(Some tests converted to splitunc() tests.)
* Lib/ntpath.py:
Withdraw the UNC support from splitdrive(). Instead, a new function
splitunc() parses UNC paths. The contributor of the UNC parsing in
splitdrive() doesn't like it, but I haven't heard a good reason to
keep it, and it causes some problems. (I think there's a
philosophical problem -- to me, the split*() functions are purely
syntactical, and the fact that \\foo is not a valid path doesn't mean
that it shouldn't be considered an absolute path.)
Also (quite separately, but strangely related to the philosophical
issue above) fix abspath() so that if win32api exists, it doesn't fail
when the path doesn't actually exist -- if GetFullPathName() fails,
fall back on the old strategy (join with getcwd() if neccessary, and
then use normpath()).
* configure.in, configure, config.h.in, acconfig.h:
For BeOS PowerPC. Chris Herborth.
Mon Apr 5 21:54:14 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Modules/timemodule.c:
Jonathan Giddy notes, and Chris Lawrence agrees, that some comments on
#else/#endif are wrong, and that #if HAVE_TM_ZONE should be #ifdef.
* Misc/ACKS:
Bunch of new contributors, including 9 who contributed to the Docs,
reported by Fred.
Mon Apr 5 18:37:59 1999 Fred Drake <fdrake@eric.cnri.reston.va.us>
* Lib/gzip.py:
Oops, missed mode parameter to open().
* Lib/gzip.py:
Made the default mode 'rb' instead of 'r', for better cross-platform
support. (Based on comment on the documentation by Bernhard Reiter
<bernhard@csd.uwm.edu>).
Fri Apr 2 22:18:25 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Tools/scripts/dutree.py:
For reasons I dare not explain, this script should always execute
main() when imported (in other words, it is not usable as a module).
Thu Apr 1 15:32:30 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/test/test_cpickle.py: Jonathan Giddy write:
In test_cpickle.py, the module os got imported, but the line to remove
the temp file has gone missing.
Tue Mar 30 20:17:31 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/BaseHTTPServer.py: Per Cederqvist writes:
If you send something like "PUT / HTTP/1.0" to something derived from
BaseHTTPServer that doesn't define do_PUT, you will get a response
that begins like this:
HTTP/1.0 501 Unsupported method ('do_PUT')
Server: SimpleHTTP/0.3 Python/1.5
Date: Tue, 30 Mar 1999 18:53:53 GMT
The server should complain about 'PUT' instead of 'do_PUT'. This
patch should fix the problem.
Mon Mar 29 20:33:21 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/smtplib.py: Patch by Per Cederqvist, who writes:
"""
- It needlessly used the makefile() method for each response that is
read from the SMTP server.
- If the remote SMTP server closes the connection unexpectedly the
code raised an IndexError. It now raises an SMTPServerDisconnected
exception instead.
- The code now checks that all lines in a multiline response actually
contains an error code.
"""
The Dragon approves.
Mon Mar 29 20:25:40 1999 Fred Drake <fdrake@eric.cnri.reston.va.us>
* Lib/compileall.py:
When run as a script, report failures in the exit code as well.
Patch largely based on changes by Andrew Dalke, as discussed in the
distutils-sig.
Mon Mar 29 20:23:41 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/urllib.py:
Hack so that if a 302 or 301 redirect contains a relative URL, the
right thing "just happens" (basejoin() with old URL).
* Modules/cPickle.c:
Protection against picling to/from closed (real) file.
The problem was reported by Moshe Zadka.
* Lib/test/test_cpickle.py:
Test protection against picling to/from closed (real) file.
* Modules/timemodule.c: Chris Lawrence writes:
"""
The GNU folks, in their infinite wisdom, have decided not to implement
altzone in libc6; this would not be horrible, except that timezone
(which is implemented) includes the current DST setting (i.e. timezone
for Central is 18000 in summer and 21600 in winter). So Python's
timezone and altzone variables aren't set correctly during DST.
Here's a patch relative to 1.5.2b2 that (a) makes timezone and altzone
show the "right" thing on Linux (by using the tm_gmtoff stuff
available in BSD, which is how the GLIBC manual claims things should
be done) and (b) should cope with the southern hemisphere. In pursuit
of (b), I also took the liberty of renaming the "summer" and "winter"
variables to "july" and "jan". This patch should also make certain
time calculations on Linux actually work right (like the tz-aware
functions in the rfc822 module).
(It's hard to find DST that's currently being used in the southern
hemisphere; I tested using Africa/Windhoek.)
"""
* Lib/test/output/test_gzip:
Jonathan Giddy discovered this file was missing.
* Modules/shamodule.c:
Avoid warnings from AIX compiler. Reported by Vladimir (AIX is my
middlename) Marangozov, patch coded by Greg Stein.
* Tools/idle/ScriptBinding.py, Tools/idle/PyShell.py:
At Tim Peters' recommendation, add a dummy flush() method to PseudoFile.
Sun Mar 28 17:55:32 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Tools/scripts/ndiff.py: Tim Peters writes:
I should have waited overnight <wink/sigh>. Nothing wrong with the one I
sent, but I couldn't resist going on to add new -r1 / -r2 cmdline options
for recreating the original files from ndiff's output. That's attached, if
you're game! Us Windows guys don't usually have a sed sitting around
<wink>.
Sat Mar 27 13:34:01 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Tools/scripts/ndiff.py: Tim Peters writes:
Attached is a cleaned-up version of ndiff (added useful module
docstring, now echo'ed in case of cmd line mistake); added -q option
to suppress initial file identification lines; + other minor cleanups,
& a slightly faster match engine.
Fri Mar 26 22:36:00 1999 Fred Drake <fdrake@eric.cnri.reston.va.us>
* Tools/scripts/dutree.py:
During display, if EPIPE is raised, it's probably because a pager was
killed. Discard the error in that case, but propogate it otherwise.
Fri Mar 26 16:20:45 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/test/output/test_userlist, Lib/test/test_userlist.py:
Test suite for UserList.
* Lib/UserList.py: Use isinstance() where appropriate.
Reformatted with 4-space indent.
Fri Mar 26 16:11:40 1999 Barry Warsaw <bwarsaw@eric.cnri.reston.va.us>
* Tools/pynche/PyncheWidget.py:
Helpwin.__init__(): The text widget should get focus.
* Tools/pynche/pyColorChooser.py:
Removed unnecessary import `from PyncheWidget import PyncheWidget'
Fri Mar 26 15:32:05 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/test/output/test_userdict, Lib/test/test_userdict.py:
Test suite for UserDict
* Lib/UserDict.py: Improved a bunch of things.
The constructor now takes an optional dictionary.
Use isinstance() where appropriate.
Thu Mar 25 22:38:49 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/test/output/test_pickle, Lib/test/output/test_cpickle, Lib/test/test_pickle.py, Lib/test/test_cpickle.py:
Basic regr tests for pickle/cPickle
* Lib/pickle.py:
Don't use "exec" in find_class(). It's slow, unnecessary, and (as AMK
points out) it doesn't work in JPython Applets.
Thu Mar 25 21:50:27 1999 Andrew Kuchling <akuchlin@eric.cnri.reston.va.us>
* Lib/test/test_gzip.py:
Added a simple test suite for gzip. It simply opens a temp file,
writes a chunk of compressed data, closes it, writes another chunk, and
reads the contents back to verify that they are the same.
* Lib/gzip.py:
Based on a suggestion from bruce@hams.com, make a trivial change to
allow using the 'a' flag as a mode for opening a GzipFile. gzip
files, surprisingly enough, can be concatenated and then decompressed;
the effect is to concatenate the two chunks of data.
If we support it on writing, it should also be supported on reading.
This *wasn't* trivial, and required rearranging the code in the
reading path, particularly the _read() method.
Raise IOError instead of RuntimeError in two cases, 'Not a gzipped file'
and 'Unknown compression method'
Thu Mar 25 21:25:01 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/test/test_b1.py:
Add tests for float() and complex() with string args (Nick/Stephanie
Lockwood).
Thu Mar 25 21:21:08 1999 Andrew Kuchling <akuchlin@eric.cnri.reston.va.us>
* Modules/zlibmodule.c:
Add an .unused_data attribute to decompressor objects. If .unused_data
is not an empty string, this means that you have arrived at the
end of the stream of compressed data, and the contents of .unused_data are
whatever follows the compressed stream.
Thu Mar 25 21:16:07 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Python/bltinmodule.c:
Patch by Nick and Stephanie Lockwood to implement complex() with a string
argument. This closes TODO item 2.19.
Wed Mar 24 19:09:00 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Tools/webchecker/wcnew.py: Added Samuel Bayer's new webchecker.
Unfortunately his code breaks wcgui.py in a way that's not easy
to fix. I expect that this is a temporary situation --
eventually Sam's changes will be merged back in.
(The changes add a -t option to specify exceptions to the -x
option, and explicit checking for #foo style fragment ids.)
* Objects/dictobject.c:
Vladimir Marangozov contributed updated comments.
* Objects/bufferobject.c: Folded long lines.
* Lib/test/output/test_sha, Lib/test/test_sha.py:
Added Jeremy's test code for the sha module.
* Modules/shamodule.c, Modules/Setup.in:
Added Greg Stein and Andrew Kuchling's sha module.
Fix comments about zlib version and URL.
* Lib/test/test_bsddb.py: Remove the temp file when we're done.
* Include/pythread.h: Conform to standard boilerplate.
* configure.in, configure, BeOS/linkmodule, BeOS/ar-fake:
Chris Herborth: the new compiler in R4.1 needs some new options to work...
* Modules/socketmodule.c:
Implement two suggestions by Jonathan Giddy: (1) in AIX, clear the
data struct before calling gethostby{name,addr}_r(); (2) ignore the
3/5/6 args determinations made by the configure script and switch on
platform identifiers instead:
AIX, OSF have 3 args
Sun, SGI have 5 args
Linux has 6 args
On all other platforms, undef HAVE_GETHOSTBYNAME_R altogether.
* Modules/socketmodule.c:
Vladimir Marangozov implements the AIX 3-arg gethostbyname_r code.
* Lib/mailbox.py:
Add readlines() to _Subfile class. Not clear who would need it, but
Chris Lawrence sent me a broken version; this one is a tad simpler and
more conforming to the standard.
Tue Mar 23 23:05:34 1999 Jeremy Hylton <jhylton@eric.cnri.reston.va.us>
* Lib/gzip.py: use struct instead of bit-manipulate in Python
Tue Mar 23 19:00:55 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Modules/Makefile.pre.in:
Add $(EXE) to various occurrences of python so it will work on Cygwin
with egcs (after setting EXE=.exe). Patch by Norman Vine.
* configure, configure.in:
Ack! It never defined HAVE_GETHOSTBYNAME_R so that code was never tested!
Mon Mar 22 22:25:39 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Include/thread.h:
Adding thread.h -- unused but for b/w compatibility.
As requested by Bill Janssen.
* configure.in, configure:
Add code to test for all sorts of gethostbyname_r variants,
donated by David Arnold.
* config.h.in, acconfig.h:
Add symbols for gethostbyname_r variants (sigh).
* Modules/socketmodule.c: Clean up pass for the previous patches.
- Use HAVE_GETHOSTBYNAME_R_6_ARG instead of testing for Linux and
glibc2.
- If gethostbyname takes 3 args, undefine HAVE_GETHOSTBYNAME_R --
don't know what code should be used.
- New symbol USE_GETHOSTBYNAME_LOCK defined iff the lock should be used.
- Modify the gethostbyaddr() code to also hold on to the lock until
after it is safe to release, overlapping with the Python lock.
(Note: I think that it could in theory be possible that Python code
executed while gethostbyname_lock is held could attempt to reacquire
the lock -- e.g. in a signal handler or destructor. I will simply say
"don't do that then.")
* Modules/socketmodule.c: Jonathan Giddy writes:
Here's a patch to fix the race condition, which wasn't fixed by Rob's
patch. It holds the gethostbyname lock until the results are copied out,
which means that this lock and the Python global lock are held at the same
time. This shouldn't be a problem as long as the gethostbyname lock is
always acquired when the global lock is not held.
Mon Mar 22 19:25:30 1999 Andrew Kuchling <akuchlin@eric.cnri.reston.va.us>
* Modules/zlibmodule.c:
Fixed the flush() method of compression objects; the test for
the end of loop was incorrect, and failed when the flushmode != Z_FINISH.
Logic cleaned up and commented.
* Lib/test/test_zlib.py:
Added simple test for the flush() method of compression objects, trying the
different flush values Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FULL_FLUSH.
Mon Mar 22 15:28:08 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/shlex.py:
Bug reported by Tobias Thelen: missing "self." in assignment target.
Fri Mar 19 21:50:11 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Modules/arraymodule.c:
Use an unsigned cast to avoid a warning in VC++.
* Lib/dospath.py, Lib/ntpath.py:
New code for split() by Tim Peters, behaves more like posixpath.split().
* Objects/floatobject.c:
Fix a problem with Vladimir's PyFloat_Fini code: clear the free list; if
a block cannot be freed, add its free items back to the free list.
This is necessary to avoid leaking when Python is reinitialized later.
* Objects/intobject.c:
Fix a problem with Vladimir's PyInt_Fini code: clear the free list; if
a block cannot be freed, add its free items back to the free list, and
add its valid ints back to the small_ints array if they are in range.
This is necessary to avoid leaking when Python is reinitialized later.
* Lib/types.py:
Added BufferType, the type returned by the new builtin buffer(). Greg Stein.
* Python/bltinmodule.c:
New builtin buffer() creates a derived read-only buffer from any
object that supports the buffer interface (e.g. strings, arrays).
* Objects/bufferobject.c:
Added check for negative offset for PyBuffer_FromObject and check for
negative size for PyBuffer_FromMemory. Greg Stein.
Thu Mar 18 15:10:44 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/urlparse.py: Sjoerd Mullender writes:
If a filename on Windows starts with \\, it is converted to a URL
which starts with ////. If this URL is passed to urlparse.urlparse
you get a path that starts with // (and an empty netloc). If you pass
the result back to urlparse.urlunparse, you get a URL that starts with
//, which is parsed differently by urlparse.urlparse. The fix is to
add the (empty) netloc with accompanying slashes if the path in
urlunparse starts with //. Do this for all schemes that use a netloc.
* Lib/nturl2path.py: Sjoerd Mullender writes:
Pathnames of files on other hosts in the same domain
(\\host\path\to\file) are not translated correctly to URLs and back.
The URL should be something like file:////host/path/to/file.
Note that a combination of drive letter and remote host is not
possible.
Wed Mar 17 22:30:10 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/urlparse.py:
Delete non-standard-conforming code in urljoin() that would use the
netloc from the base url as the default netloc for the resulting url
even if the schemes differ.
Once upon a time, when the web was wild, this was a valuable hack
because some people had a URL referencing an ftp server colocated with
an http server without having the host in the ftp URL (so they could
replicate it or change the hostname easily).
More recently, after the file: scheme got added back to the list of
schemes that accept a netloc, it turns out that this caused weirdness
when joining an http: URL with a file: URL -- the resulting file: URL
would always inherit the host from the http: URL because the file:
scheme supports a netloc but in practice never has one.
There are two reasons to get rid of the old, once-valuable hack,
instead of removing the file: scheme from the uses_netloc list. One,
the RFC says that file: uses the netloc syntax, and does not endorse
the old hack. Two, neither netscape 4.5 nor IE 4.0 support the old
hack.
* Include/ceval.h, Include/abstract.h:
Add DLL level b/w compat for PySequence_In and PyEval_CallObject
Tue Mar 16 21:54:50 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/lib-tk/Tkinter.py: Bug reported by Jim Robinson:
An attempt to execute grid_slaves with arguments (0,0) results in
*all* of the slaves being returned, not just the slave associated with
row 0, column 0. This is because the test for arguments in the method
does not test to see if row (and column) does not equal None, but
rather just whether is evaluates to non-false. A value of 0 fails
this test.
Tue Mar 16 14:17:48 1999 Fred Drake <fdrake@eric.cnri.reston.va.us>
* Modules/cmathmodule.c:
Docstring fix: acosh() returns the hyperbolic arccosine, not the
hyperbolic cosine. Problem report via David Ascher by one of his
students.
Mon Mar 15 21:40:59 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* configure.in:
Should test for gethost*by*name_r, not for gethostname_r (which
doesn't exist and doesn't make sense).
* Modules/socketmodule.c:
Patch by Rob Riggs for Linux -- glibc2 has a different argument
converntion for gethostbyname_r() etc. than Solaris!
* Python/thread_pthread.h: Rob Riggs wrote:
"""
Spec says that on success pthread_create returns 0. It does not say
that an error code will be < 0. Linux glibc2 pthread_create() returns
ENOMEM (12) when one exceed process limits. (It looks like it should
return EAGAIN, but that's another story.)
For reference, see:
http://www.opengroup.org/onlinepubs/7908799/xsh/pthread_create.html
"""
[I have a feeling that similar bugs were fixed before; perhaps someone
could check that all error checks no check for != 0?]
* Tools/bgen/bgen/bgenObjectDefinition.py:
New mixin class that defines cmp and hash that use
the ob_itself pointer. This allows (when using the mixin)
different Python objects pointing to the same C object and
behaving well as dictionary keys.
Or so sez Jack Jansen...
* Lib/urllib.py: Yet another patch by Sjoerd Mullender:
Don't convert URLs to URLs using pathname2url.
Fri Mar 12 22:15:43 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/cmd.py: Patch by Michael Scharf. He writes:
The module cmd requires for each do_xxx command a help_xxx
function. I think this is a little old fashioned.
Here is a patch: use the docstring as help if no help_xxx
function can be found.
[I'm tempted to rip out all the help_* functions from pdb, but I'll
resist it. Any takers? --Guido]
* Tools/freeze/freeze.py: Bug submitted by Wayne Knowles, who writes:
Under Windows, python freeze.py -o hello hello.py
creates all the correct files in the hello subdirectory, but the
Makefile has the directory prefix in it for frozen_extensions.c
nmake fails because it tries to locate hello/frozen_extensions.c
(His fix adds a call to os.path.basename() in the appropriate place.)
* Objects/floatobject.c, Objects/intobject.c:
Vladimir has restructured his code somewhat so that the blocks are now
represented by an explicit structure. (There are still too many casts
in the code, but that may be unavoidable.)
Also added code so that with -vv it is very chatty about what it does.
* Demo/zlib/zlibdemo.py, Demo/zlib/minigzip.py:
Change #! line to modern usage; also chmod +x
* Demo/pdist/rrcs, Demo/pdist/rcvs, Demo/pdist/rcsbump:
Change #! line to modern usage
* Lib/nturl2path.py, Lib/urllib.py: From: Sjoerd Mullender
The filename to URL conversion didn't properly quote special
characters.
The URL to filename didn't properly unquote special chatacters.
* Objects/floatobject.c:
OK, try again. Vladimir gave me a fix for the alignment bus error,
so here's his patch again. This time it works (at least on Solaris,
Linux and Irix).
Thu Mar 11 23:21:23 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Tools/idle/PathBrowser.py:
Don't crash when sys.path contains an empty string.
* Tools/idle/PathBrowser.py:
- Don't crash in the case where a superclass is a string instead of a
pyclbr.Class object; this can happen when the superclass is
unrecognizable (to pyclbr), e.g. when module renaming is used.
- Show a watch cursor when calling pyclbr (since it may take a while
recursively parsing imported modules!).
Thu Mar 11 16:04:04 1999 Fred Drake <fdrake@eric.cnri.reston.va.us>
* Lib/mimetypes.py:
Added .rdf and .xsl as application/xml types. (.rdf is for the
Resource Description Framework, a metadata encoding, and .xsl is for
the Extensible Stylesheet Language.)
Thu Mar 11 13:26:23 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/test/output/test_popen2, Lib/test/test_popen2.py:
Test for popen2 module, by Chris Tismer.
* Objects/floatobject.c:
Alas, Vladimir's patch caused a bus error (probably double
alignment?), and I didn't test it. Withdrawing it for now.
Wed Mar 10 22:55:47 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Objects/floatobject.c:
Patch by Vladimir Marangoz to allow freeing of the allocated blocks of
floats on finalization.
* Objects/intobject.c:
Patch by Vladimir Marangoz to allow freeing of the allocated blocks of
integers on finalization.
* Tools/idle/EditorWindow.py, Tools/idle/Bindings.py:
Add PathBrowser to File module
* Tools/idle/PathBrowser.py:
"Path browser" - 4 scrolled lists displaying:
directories on sys.path
modules in selected directory
classes in selected module
methods of selected class
Sinlge clicking in a directory, module or class item updates the next
column with info about the selected item. Double clicking in a
module, class or method item opens the file (and selects the clicked
item if it is a class or method).
I guess eventually I should be using a tree widget for this, but the
ones I've seen don't work well enough, so for now I use the old
Smalltalk or NeXT style multi-column hierarchical browser.
* Tools/idle/MultiScrolledLists.py:
New utility: multiple scrolled lists in parallel
* Tools/idle/ScrolledList.py: - White background.
- Display "(None)" (or text of your choosing) when empty.
- Don't set the focus.
Tue Mar 9 19:31:21 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/urllib.py:
open_http also had the 'data is None' test backwards. don't call with the
extra argument if data is None.
* Demo/embed/demo.c:
Call Py_SetProgramName() instead of redefining getprogramname(),
reflecting changes in the runtime around 1.5 or earlier.
* Python/ceval.c:
Always test for an error return (usually NULL or -1) without setting
an exception.
* Modules/timemodule.c: Patch by Chris Herborth for BeOS code.
He writes:
I had an off-by-1000 error in floatsleep(),
and the problem with time.clock() is that it's not implemented properly
on QNX... ANSI says it's supposed to return _CPU_ time used by the
process, but on QNX it returns the amount of real time used... so I was
confused.
* Tools/bgen/bgen/macsupport.py: Small change by Jack Jansen.
Test for self.returntype behaving like OSErr rather than being it.
Thu Feb 25 16:14:58 1999 Jeremy Hylton <jhylton@eric.cnri.reston.va.us>
* Lib/urllib.py:
http_error had the 'data is None' test backwards. don't call with the
extra argument if data is None.
* Lib/urllib.py: change indentation from 8 spaces to 4 spaces
* Lib/urllib.py: pleasing the tabnanny
Thu Feb 25 14:26:02 1999 Fred Drake <fdrake@eric.cnri.reston.va.us>
* Lib/colorsys.py:
Oops, one more "x, y, z" to convert...
* Lib/colorsys.py:
Adjusted comment at the top to be less confusing, following Fredrik
Lundh's example.
Converted comment to docstring.
Wed Feb 24 18:49:15 1999 Fred Drake <fdrake@eric.cnri.reston.va.us>
* Lib/toaiff.py:
Use sndhdr instead of the obsolete whatsound module.
Wed Feb 24 18:42:38 1999 Jeremy Hylton <jhylton@eric.cnri.reston.va.us>
* Lib/urllib.py:
When performing a POST request, i.e. when the second argument to
urlopen is used to specify form data, make sure the second argument is
threaded through all of the http_error_NNN calls. This allows error
handlers like the redirect and authorization handlers to properly
re-start the connection.
Wed Feb 24 16:25:17 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/mhlib.py: Patch by Lars Wirzenius:
o the initial comment is wrong: creating messages is already
implemented
o Message.getbodytext: if the mail or it's part contains an
empty content-transfer-encoding header, the code used to
break; the change below treats an empty encoding value the same
as the other types that do not need decoding
o SubMessage.getbodytext was missing the decode argument; the
change below adds it; I also made it unconditionally return
the raw text if decoding was not desired, because my own
routines needed that (and it was easier than rewriting my
own routines ;-)
Wed Feb 24 00:35:43 1999 Barry Warsaw <bwarsaw@eric.cnri.reston.va.us>
* Python/bltinmodule.c (initerrors):
Make sure that the exception tuples ("base-classes" when
string-based exceptions are used) reflect the real class hierarchy,
i.e. that SystemExit derives from Exception not StandardError.
* Lib/exceptions.py:
Document the correct class hierarchy for SystemExit. It is not an
error and so it derives from Exception and not SystemError. The
docstring was incorrect but the implementation was fine.
Tue Feb 23 23:07:51 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/shutil.py:
Add import sys, needed by reference to sys.exc_info() in rmtree().
Discovered by Mitch Chapman.
* config.h.in:
Now that we don't have AC_CHECK_LIB(m, pow), the HAVE_LIBM symbol
disappears. It wasn't used anywhere anyway...
* Modules/arraymodule.c:
Carefully check for overflow when allocating the memory for fromfile
-- someone tried to pass in sys.maxint and got bitten by the bogus
calculations.
* configure.in:
Get rid of AC_CHECK_LIB(m, pow) since this is taken care of later with
LIBM (from --with-libm=...); this actually broke the customizability
offered by the latter option. Thanks go to Clay Spence for reporting
this.
* Lib/test/test_dl.py:
1. Print the error message (carefully) when a dl.open() fails in verbose mode.
2. When no test case worked, raise ImportError instead of failing.
* Python/bltinmodule.c:
Patch by Tim Peters to improve the range checks for range() and
xrange(), especially for platforms where int and long are different
sizes (so sys.maxint isn't actually the theoretical limit for the
length of a list, but the largest C int is -- sys.maxint is the
largest Python int, which is actually a C long).
* Makefile.in:
1. Augment the DG/UX rule so it doesn't break the BeOS build.
2. Add $(EXE) to various occurrences of python so it will work on
Cygwin with egcs (after setting EXE=.exe). These patches by
Norman Vine.
* Lib/posixfile.py:
According to Jeffrey Honig, bsd/os 2.0 - 4.0 should be added to the
list (of bsd variants that have a different lock structure).
* Lib/test/test_fcntl.py:
According to Jeffrey Honig, bsd/os 4.0 should be added to the list.
* Modules/timemodule.c:
Patch by Tadayoshi Funaba (with some changes) to be smarter about
guessing what happened when strftime() returns 0. Is it buffer
overflow or was the result simply 0 bytes long? (This happens for an
empty format string, or when the format string is a single %Z and the
timezone is unknown.) if the buffer is at least 256 times as long as
the format, assume the latter.
Mon Feb 22 19:01:42 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/urllib.py:
As Des Barry points out, we need to call pathname2url(file) in two
calls to addinfourl() in open_file().
* Modules/Setup.in: Document *static* -- in two places!
* Modules/timemodule.c:
We don't support leap seconds, so the seconds field of a time 9-tuple
should be in the range [0-59]. Noted by Tadayoshi Funaba.
* Modules/stropmodule.c:
In atoi(), don't use isxdigit() to test whether the last character
converted was a "digit" -- use isalnum(). This test is there only to
guard against "+" or "-" being interpreted as a valid int literal.
Reported by Takahiro Nakayama.
* Lib/os.py:
As Finn Bock points out, _P_WAIT etc. don't have a leading underscore
so they don't need to be treated specially here.
Mon Feb 22 15:38:58 1999 Fred Drake <fdrake@eric.cnri.reston.va.us>
* Misc/NEWS:
Typo: "apparentlt" --> "apparently"
Mon Feb 22 15:38:46 1999 Guido van Rossum <guido@eric.cnri.reston.va.us>
* Lib/urlparse.py: Steve Clift pointed out that 'file' allows a netloc.
* Modules/posixmodule.c:
The docstring for ttyname(..) claims a second "mode" argument. The
actual code does not allow such an argument. (Finn Bock.)
* Lib/lib-old/poly.py:
Dang. Even though this is obsolete code, somebody found a bug, and I
fix it. Oh well.
Thu Feb 18 20:51:50 1999 Fred Drake <fdrake@eric.cnri.reston.va.us>
* Lib/pyclbr.py:
Bow to font-lock at the end of the docstring, since it throws stuff
off.
Make sure the path paramter to readmodule() is a list before adding it
with sys.path, or the addition could fail.
======================================================================
From 1.5.2b1 to 1.5.2b2
=======================
General
-------
- Many memory leaks fixed.
- Many small bugs fixed.
- Command line option -OO (or -O -O) suppresses inclusion of doc
strings in resulting bytecode.
Windows-specific changes
------------------------
- New built-in module winsound provides an interface to the Win32
PlaySound() call.
- Re-enable the audioop module in the config.c file.
- On Windows, support spawnv() and associated P_* symbols.
- Fixed the conversion of times() return values on Windows.
- Removed freeze from the installer -- it doesn't work without the
source tree. (See FAQ 8.11.)
- On Windows 95/98, the Tkinter module now is smart enough to find
Tcl/Tk even when the PATH environment variable hasn't been set -- when
the import of _tkinter fails, it searches in a standard locations,
patches os.environ["PATH"], and tries again. When it still fails, a
clearer error message is produced. This should avoid most
installation problems with Tkinter use (e.g. in IDLE).
- The -i option doesn't make any calls to set[v]buf() for stdin --
this apparently screwed up _kbhit() and the _tkinter main loop.
- The ntpath module (and hence, os.path on Windows) now parses out UNC
paths (e.g. \\host\mountpoint\dir\file) as "drive letters", so that
splitdrive() will \\host\mountpoint as the drive and \dir\file as the
path. ** EXPERIMENTAL **
- Added a hack to the exit code so that if (1) the exit status is
nonzero and (2) we think we have our own DOS box (i.e. we're not
started from a command line shell), we print a message and wait for
the user to hit a key before the DOS box is closed.
- Updated the installer to WISE 5.0g. Added a dialog warning about
the imminent Tcl installation. Added a dialog to specify the program
group name in the start menu. Upgraded the Tcl installer to Tcl
8.0.4.
Changes to intrinsics
---------------------
- The repr() or str() of a module object now shows the __file__
attribute (i.e., the file which it was loaded), or the string
"(built-in)" if there is no __file__ attribute.
- The range() function now avoids overflow during its calculations (if
at all possible).
- New info string sys.hexversion, which is an integer encoding the
version in hexadecimal. In other words, hex(sys.hexversion) ==
0x010502b2 for Python 1.5.2b2.
New or improved ports
---------------------
- Support for Nextstep descendants (future Mac systems).
- Improved BeOS support.
- Support dynamic loading of shared libraries on NetBSD platforms that
use ELF (i.e., MIPS and Alpha systems).
Configuration/build changes
---------------------------
- The Lib/test directory is no longer included in the default module
search path (sys.path) -- "test" has been a package ever since 1.5.
- Now using autoconf 2.13.
New library modules
-------------------
- New library modules asyncore and asynchat: these form Sam Rushing's
famous asynchronous socket library. Sam has gracefully allowed me to
incorporate these in the standard Python library.
- New module statvfs contains indexing constants for [f]statvfs()
return tuple.
Changes to the library
----------------------
- The wave module (platform-independent support for Windows sound
files) has been fixed to actually make it work.
- The sunau module (platform-independent support for Sun/NeXT sound
files) has been fixed to work across platforms. Also, a weird
encoding bug in the header of the audio test data file has been
corrected.
- Fix a bug in the urllib module that occasionally tripped up
webchecker and other ftp retrieves.
- ConfigParser's get() method now accepts an optional keyword argument
(vars) that is substituted on top of the defaults that were setup in
__init__. You can now also have recusive references in your
configuration file.
- Some improvements to the Queue module, including a put_nowait()
module and an optional "block" second argument, to get() and put(),
defaulting to 1.
- The updated xmllib module is once again compatible with the version
present in Python 1.5.1 (this was accidentally broken in 1.5.2b1).
- The bdb module (base class for the debugger) now supports
canonicalizing pathnames used in breakpoints. The derived class must
override the new canonical() method for this to work. Also changed
clear_break() to the backwards compatible old signature, and added
clear_bpbynumber() for the new functionality.
- In sgmllib (and hence htmllib), recognize attributes even if they
don't have space in front of them. I.e. '<a
name="foo"href="bar.html">' will now have two attributes recognized.
- In the debugger (pdb), change clear syntax to support three
alternatives: clear; clear file:line; clear bpno bpno ...
- The os.path module now pretends to be a submodule within the os
"package", so you can do things like "from os.path import exists".
- The standard exceptions now have doc strings.
- In the smtplib module, exceptions are now classes. Also avoid
inserting a non-standard space after "TO" in rcpt() command.
- The rfc822 module's getaddrlist() method now uses all occurrences of
the specified header instead of just the first. Some other bugfixes
too (to handle more weird addresses found in a very large test set,
and to avoid crashes on certain invalid dates), and a small test
module has been added.
- Fixed bug in urlparse in the common-case code for HTTP URLs; it
would lose the query, fragment, and/or parameter information.
- The sndhdr module no longer supports whatraw() -- it depended on a
rare extenral program.
- The UserList module/class now supports the extend() method, like
real list objects.
- The uu module now deals better with trailing garbage generated by
some broke uuencoders.
- The telnet module now has an my_interact() method which uses threads
instead of select. The interact() method uses this by default on
Windows (where the single-threaded version doesn't work).
- Add a class to mailbox.py for dealing with qmail directory
mailboxes. The test code was extended to notice these being used as
well.
Changes to extension modules
----------------------------
- Support for the [f]statvfs() system call, where it exists.
- Fixed some bugs in cPickle where bad input could cause it to dump
core.
- Fixed cStringIO to make the writelines() function actually work.
- Added strop.expandtabs() so string.expandtabs() is now much faster.
- Added fsync() and fdatasync(), if they appear to exist.
- Support for "long files" (64-bit seek pointers).
- Fixed a bug in the zlib module's flush() function.
- Added access() system call. It returns 1 if access granted, 0 if
not.
- The curses module implements an optional nlines argument to
w.scroll(). (It then calls wscrl(win, nlines) instead of scoll(win).)
Changes to tools
----------------
- Some changes to IDLE; see Tools/idle/NEWS.txt.
- Latest version of Misc/python-mode.el included.
Changes to Tkinter
------------------
- Avoid tracebacks when an image is deleted after its root has been
destroyed.
Changes to the Python/C API
---------------------------
- When parentheses are used in a PyArg_Parse[Tuple]() call, any
sequence is now accepted, instead of requiring a tuple. This is in
line with the general trend towards accepting arbitrary sequences.
- Added PyModule_GetFilename().
- In PyNumber_Power(), remove unneeded and even harmful test for float
to the negative power (which is already and better done in
floatobject.c).
- New version identification symbols; read patchlevel.h for info. The
version numbers are now exported by Python.h.
- Rolled back the API version change -- it's back to 1007!
- The frozenmain.c function calls PyInitFrozenExtensions().
- Added 'N' format character to Py_BuildValue -- like 'O' but doesn't
INCREF.
======================================================================
From 1.5.2a2 to 1.5.2b1
=======================
Changes to intrinsics
---------------------
- New extension NotImplementedError, derived from RuntimeError. Not
used, but recommended use is for "abstract" methods to raise this.
- The parser will now spit out a warning or error when -t or -tt is
used for parser input coming from a string, too.
- The code generator now inserts extra SET_LINENO opcodes when
compiling multi-line argument lists.
- When comparing bound methods, use identity test on the objects, not
equality test.
New or improved ports
---------------------
- Chris Herborth has redone his BeOS port; it now works on PowerPC
(R3/R4) and x86 (R4 only). Threads work too in this port.
Renaming
--------
- Thanks to Chris Herborth, the thread primitives now have proper Py*
names in the source code (they already had those for the linker,
through some smart macros; but the source still had the old, un-Py
names).
Configuration/build changes
---------------------------
- Improved support for FreeBSD/3.
- Check for pthread_detach instead of pthread_create in libc.
- The makesetup script now searches EXECINCLUDEPY before INCLUDEPY.
- Misc/Makefile.pre.in now also looks at Setup.thread and Setup.local.
Otherwise modules such as thread didn't get incorporated in extensions.
New library modules
-------------------
- shlex.py by Eric Raymond provides a lexical analyzer class for
simple shell-like syntaxes.
- netrc.py by Eric Raymond provides a parser for .netrc files. (The
undocumented Netrc class in ftplib.py is now obsolete.)
- codeop.py is a new module that contains the compile_command()
function that was previously in code.py. This is so that JPython can
provide its own version of this function, while still sharing the
higher-level classes in code.py.
- turtle.py is a new module for simple turtle graphics. I'm still
working on it; let me know if you use this to teach Python to children
or other novices without prior programming experience.
Obsoleted library modules
-------------------------
- poly.py and zmod.py have been moved to Lib/lib-old to emphasize
their status of obsoleteness. They don't do a particularly good job
and don't seem particularly relevant to the Python core.
New tools
---------
- I've added IDLE: my Integrated DeveLopment Environment for Python.
Requires Tcl/Tk (and Tkinter). Works on Windows and Unix (and should
work on Macintosh, but I haven't been able to test it there; it does
depend on new features in 1.5.2 and perhaps even new features in
1.5.2b1, especially the new code module). This is very much a work in
progress. I'd like to hear how people like it compared to PTUI (or
any other IDE they are familiar with).
- New tools by Barry Warsaw:
= audiopy: controls the Solaris Audio device
= pynche: The PYthonically Natural Color and Hue Editor
= world: Print mappings between country names and DNS country codes
New demos
---------
- Demo/scripts/beer.py prints the lyrics to an arithmetic drinking
song.
- Demo/tkinter/guido/optionmenu.py shows how to do an option menu in
Tkinter. (By Fredrik Lundh -- not by me!)
Changes to the library
----------------------
- compileall.py now avoids recompiling .py files that haven't changed;
it adds a -f option to force recompilation.
- New version of xmllib.py by Sjoerd Mullender (0.2 with latest
patches).
- nntplib.py: statparse() no longer lowercases the message-id.
- types.py: use type(__stdin__) for FileType.
- urllib.py: fix translations for filenames with "funny" characters.
Patch by Sjoerd Mullender. Note that if you subclass one of the
URLopener classes, and you have copied code from the old urllib.py,
your subclass may stop working. A long-term solution is to provide
more methods so that you don't have to copy code.
- cgi.py: In read_multi, allow a subclass to override the class we
instantiate when we create a recursive instance, by setting the class
variable 'FieldStorageClass' to the desired class. By default, this
is set to None, in which case we use self.__class__ (as before).
Also, a patch by Jim Fulton to pass additional arguments to recursive
calls to the FieldStorage constructor from its read_multi method.
- UserList.py: In __getslice__, use self.__class__ instead of
UserList.
- In SimpleHTTPServer.py, the server specified in test() should be
BaseHTTPServer.HTTPServer, in case the request handler should want to
reference the two attributes added by BaseHTTPServer.server_bind. (By
Jeff Rush, for Bobo). Also open the file in binary mode, so serving
images from a Windows box might actually work.
- In CGIHTTPServer.py, the list of acceptable formats is -split-
on spaces but -joined- on commas, resulting in double commas
in the joined text. (By Jeff Rush.)
- SocketServer.py, patch by Jeff Bauer: a minor change to declare two
new threaded versions of Unix Server classes, using the ThreadingMixIn
class: ThreadingUnixStreamServer, ThreadingUnixDatagramServer.
- bdb.py: fix bomb on deleting a temporary breakpoint: there's no
method do_delete(); do_clear() was meant. By Greg Ward.
- getopt.py: accept a non-list sequence for the long options (request
by Jack Jansen). Because it might be a common mistake to pass a
single string, this situation is treated separately. Also added
docstrings (copied from the library manual) and removed the (now
redundant) module comments.
- tempfile.py: improvements to avoid security leaks.
- code.py: moved compile_command() to new module codeop.py.
- pickle.py: support pickle format 1.3 (binary float added). By Jim
Fulton. Also get rid of the undocumented obsolete Pickler dump_special
method.
- uu.py: Move 'import sys' to top of module, as noted by Tim Peters.
- imaplib.py: fix problem with some versions of IMAP4 servers that
choose to mix the case in their CAPABILITIES response.
- cmp.py: use (f1, f2) as cache key instead of f1 + ' ' + f2. Noted
by Fredrik Lundh.
Changes to extension modules
----------------------------
- More doc strings for several modules were contributed by Chris
Petrilli: math, cmath, fcntl.
- Fixed a bug in zlibmodule.c that could cause core dumps on
decompression of rarely occurring input.
- cPickle.c: new version from Jim Fulton, with Open Source copyright
notice. Also, initialize self->safe_constructors early on to prevent
crash in early dealloc.
- cStringIO.c: new version from Jim Fulton, with Open Source copyright
notice. Also fixed a core dump in cStringIO.c when doing seeks.
- mpzmodule.c: fix signed character usage in mpz.mpz(stringobjecty).
- readline.c: Bernard Herzog pointed out that rl_parse_and_bind
modifies its argument string (bad function!), so we make a temporary
copy.
- sunaudiodev.c: Barry Warsaw added more smarts to get the device and
control pseudo-device, per audio(7I).
Changes to tools
----------------
- New, improved version of Barry Warsaw's Misc/python-mode.el (editing
support for Emacs).
- tabnanny.py: added a -q ('quiet') option to tabnanny, which causes
only the names of offending files to be printed.
- freeze: when printing missing modules, also print the module they
were imported from.
- untabify.py: patch by Detlef Lannert to implement -t option
(set tab size).
Changes to Tkinter
------------------
- grid_bbox(): support new Tk API: grid bbox ?column row? ?column2
row2?
- _tkinter.c: RajGopal Srinivasan noted that the latest code (1.5.2a2)
doesn't work when running in a non-threaded environment. He added
some #ifdefs that fix this.
Changes to the Python/C API
---------------------------
- Bumped API version number to 1008 -- enough things have changed!
- There's a new macro, PyThreadState_GET(), which does the same work
as PyThreadState_Get() without the overhead of a function call (it
also avoids the error check). The two top calling locations of
PyThreadState_Get() have been changed to use this macro.
- All symbols intended for export from a DLL or shared library are now
marked as such (with the DL_IMPORT() macro) in the header file that
declares them. This was needed for the BeOS port, and should also
make some other ports easier. The PC port no longer needs the file
with exported symbols (PC/python_nt.def). There's also a DL_EXPORT
macro which is only used for init methods in extension modules, and
for Py_Main().
Invisible changes to internals
------------------------------
- Fixed a bug in new_buffersize() in fileobject.c which could
return a buffer size that was way too large.
- Use PySys_WriteStderr instead of fprintf in most places.
- dictobject.c: remove dead code discovered by Vladimir Marangozov.
- tupleobject.c: make tuples less hungry -- an extra item was
allocated but never used. Tip by Vladimir Marangozov.
- mymath.h: Metrowerks PRO4 finally fixes the hypot snafu. (Jack
Jansen)
- import.c: Jim Fulton fixes a reference count bug in
PyEval_GetGlobals.
- glmodule.c: check in the changed version after running the stubber
again -- this solves the conflict with curses over the 'clear' entry
point much nicer. (Jack Jansen had checked in the changes to cstubs
eons ago, but I never regenrated glmodule.c :-( )
- frameobject.c: fix reference count bug in PyFrame_New. Vladimir
Marangozov.
- stropmodule.c: add a missing DECREF in an error exit. Submitted by
Jonathan Giddy.
======================================================================
From 1.5.2a1 to 1.5.2a2
=======================
General
-------
- It is now a syntax error to have a function argument without a
default following one with a default.
- __file__ is now set to the .py file if it was parsed (it used to
always be the .pyc/.pyo file).
- Don't exit with a fatal error during initialization when there's a
problem with the exceptions.py module.
- New environment variable PYTHONOPTIMIZE can be used to set -O.
- New version of python-mode.el for Emacs.
Miscellaneous fixed bugs
------------------------
- No longer print the (confusing) error message about stack underflow
while compiling.
- Some threading and locking bugs fixed.
- When errno is zero, report "Error", not "Success".
Documentation
-------------
- Documentation will be released separately.
- Doc strings added to array and md5 modules by Chris Petrilli.
Ports and build procedure
-------------------------
- Stop installing when a move or copy fails.
- New version of the OS/2 port code by Jeff Rush.
- The makesetup script handles absolute filenames better.
- The 'new' module is now enabled by default in the Setup file.
- I *think* I've solved the problem with the Linux build blowing up
sometimes due to a conflict between sigcheck/intrcheck and
signalmodule.
Built-in functions
------------------
- The second argument to apply() can now be any sequence, not just a
tuple.
Built-in types
--------------
- Lists have a new method: L1.extend(L2) is equivalent to the common
idiom L1[len(L1):] = L2.
- Better error messages when a sequence is indexed with a non-integer.
- Bettter error message when calling a non-callable object (include
the type in the message).
Python services
---------------
- New version of cPickle.c fixes some bugs.
- pickle.py: improved instantiation error handling.
- code.py: reworked quite a bit. New base class
InteractiveInterpreter and derived class InteractiveConsole. Fixed
several problems in compile_command().
- py_compile.py: print error message and continue on syntax errors.
Also fixed an old bug with the fstat code (it was never used).
- pyclbr.py: support submodules of packages.
String Services
---------------
- StringIO.py: raise the right exception (ValueError) for attempted
I/O on closed StringIO objects.
- re.py: fixed a bug in subn(), which caused .groups() to fail inside
the replacement function called by sub().
- The struct module has a new format 'P': void * in native mode.
Generic OS Services
-------------------
- Module time: Y2K robustness. 2-digit year acceptance depends on
value of time.accept2dyear, initialized from env var PYTHONY2K,
default 0. Years 00-68 mean 2000-2068, while 69-99 mean 1969-1999
(POSIX or X/Open recommendation).
- os.path: normpath(".//x") should return "x", not "/x".
- getpass.py: fall back on default_getpass() when sys.stdin.fileno()
doesn't work.
- tempfile.py: regenerate the template after a fork() call.
Optional OS Services
--------------------
- In the signal module, disable restarting interrupted system calls
when we have siginterrupt().
Debugger
--------
- No longer set __args__; this feature is no longer supported and can
affect the debugged code.
- cmd.py, pdb.py and bdb.py have been overhauled by Richard Wolff, who
added aliases and some other useful new features, e.g. much better
breakpoint support: temporary breakpoint, disabled breakpoints,
breakpoints with ignore counts, and conditions; breakpoints can be set
on a file before it is loaded.
Profiler
--------
- Changes so that JPython can use it. Also fix the calibration code
so it actually works again
.
Internet Protocols and Support
------------------------------
- imaplib.py: new version from Piers Lauder.
- smtplib.py: change sendmail() method to accept a single string or a
list or strings as the destination (commom newbie mistake).
- poplib.py: LIST with a msg argument fixed.
- urlparse.py: some optimizations for common case (http).
- urllib.py: support content-length in info() for ftp protocol;
support for a progress meter through a third argument to
urlretrieve(); commented out gopher test (the test site is dead).
Internet Data handling
----------------------
- sgmllib.py: support tags with - or . in their name.
- mimetypes.py: guess_type() understands 'data' URLs.
Restricted Execution
--------------------
- The classes rexec.RModuleLoader and rexec.RModuleImporter no
longer exist.
Tkinter
-------
- When reporting an exception, store its info in sys.last_*. Also,
write all of it to stderr.
- Added NS, EW, and NSEW constants, for grid's sticky option.
- Fixed last-minute bug in 1.5.2a1 release: need to include "mytime.h".
- Make bind variants without a sequence return a tuple of sequences
(formerly it returned a string, which wasn't very convenient).
- Add image commands to the Text widget (these are new in Tk 8.0).
- Added new listbox and canvas methods: {xview,yview}_{scroll,moveto}.)
- Improved the thread code (but you still can't call update() from
another thread on Windows).
- Fixed unnecessary references to _default_root in the new dialog
modules.
- Miscellaneous problems fixed.
Windows General
---------------
- Call LoadLibraryEx(..., ..., LOAD_WITH_ALTERED_SEARCH_PATH) to
search for dependent dlls in the directory containing the .pyd.
- In debugging mode, call DebugBreak() in Py_FatalError().
Windows Installer
-----------------
- Install zlib.dll in the DLLs directory instead of in the win32
system directory, to avoid conflicts with other applications that have
their own zlib.dll.
Test Suite
----------
- test_long.py: new test for long integers, by Tim Peters.
- regrtest.py: improved so it can be used for other test suites as
well.
- test_strftime.py: use re to compare test results, to support legal
variants (e.g. on Linux).
Tools and Demos
---------------
- Four new scripts in Tools/scripts: crlf.py and lfcr.py (to
remove/add Windows style '\r\n' line endings), untabify.py (to remove
tabs), and rgrep.yp (reverse grep).
- Improvements to Tools/freeze/. Each Python module is now written to
its own C file. This prevents some compilers or assemblers from
blowing up on large frozen programs, and saves recompilation time if
only a few modules are changed. Other changes too, e.g. new command
line options -x and -i.
- Much improved (and smaller!) version of Tools/scripts/mailerdaemon.py.
Python/C API
------------
- New mechanism to support extensions of the type object while
remaining backward compatible with extensions compiled for previous
versions of Python 1.5. A flags field indicates presence of certain
fields.
- Addition to the buffer API to differentiate access to bytes and
8-bit characters (in anticipation of Unicode characters).
- New argument parsing format t# ("text") to indicate 8-bit
characters; s# simply means 8-bit bytes, for backwards compatibility.
- New object type, bufferobject.c is an example and can be used to
create buffers from memory.
- Some support for 64-bit longs, including some MS platforms.
- Many calls to fprintf(stderr, ...) have been replaced with calls to
PySys_WriteStderr(...).
- The calling context for PyOS_Readline() has changed: it must now be
called with the interpreter lock held! It releases the lock around
the call to the function pointed to by PyOS_ReadlineFunctionPointer
(default PyOS_StdioReadline()).
- New APIs PyLong_FromVoidPtr() and PyLong_AsVoidPtr().
- Renamed header file "thread.h" to "pythread.h".
- The code string of code objects may now be anything that supports the
buffer API.
======================================================================
From 1.5.1 to 1.5.2a1
=====================
General
-------
- When searching for the library, a landmark that is a compiled module
(string.pyc or string.pyo) is also accepted.
- When following symbolic links to the python executable, use a loop
so that a symlink to a symlink can work.
- Added a hack so that when you type 'quit' or 'exit' at the
interpreter, you get a friendly explanation of how to press Ctrl-D (or
Ctrl-Z) to exit.
- New and improved Misc/python-mode.el (Python mode for Emacs).
- Revert a new feature in Unix dynamic loading: for one or two
revisions, modules were loaded using the RTLD_GLOBAL flag. It turned
out to be a bad idea.
Miscellaneous fixed bugs
------------------------
- All patches on the patch page have been integrated. (But much more
has been done!)
- Several memory leaks plugged (e.g. the one for classes with a
__getattr__ method).
- Removed the only use of calloc(). This triggered an obscure bug on
multiprocessor Sparc Solaris 2.6.
- Fix a peculiar bug that would allow "import sys.time" to succeed
(believing the built-in time module to be a part of the sys package).
- Fix a bug in the overflow checking when converting a Python long to
a C long (failed to convert -2147483648L, and some other cases).
Documentation
-------------
- Doc strings have been added to many extension modules: __builtin__,
errno, select, signal, socket, sys, thread, time. Also to methods of
list objects (try [].append.__doc__). A doc string on a type will now
automatically be propagated to an instance if the instance has methods
that are accessed in the usual way.
- The documentation has been expanded and the formatting improved.
(Remember that the documentation is now unbundled and has its own
release cycle though; see http://www.python.org/doc/.)
- Added Misc/Porting -- a mini-FAQ on porting to a new platform.
Ports and build procedure
-------------------------
- The BeOS port is now integrated. Courtesy Chris Herborth.
- Symbol files for FreeBSD 2.x and 3.x have been contributed
(Lib/plat-freebsd[23]/*).
- Support HPUX 10.20 DCE threads.
- Finally fixed the configure script so that (on SGI) if -OPT:Olimit=0
works, it won't also use -Olimit 1500 (which gives a warning for every
file). Also support the SGI_ABI environment variable better.
- The makesetup script now understands absolute pathnames ending in .o
in the module -- it assumes it's a file for which we have no source.
- Other miscellaneous improvements to the configure script and
Makefiles.
- The test suite now uses a different sound sample.
Built-in functions
------------------
- Better checks for invalid input to int(), long(), string.atoi(),
string.atol(). (Formerly, a sign without digits would be accepted as
a legal ways to spell zero.)
- Changes to map() and filter() to use the length of a sequence only
as a hint -- if an IndexError happens earlier, take that. (Formerly,
this was considered an error.)
- Experimental feature in getattr(): a third argument can specify a
default (instead of raising AttributeError).
- Implement round() slightly different, so that for negative ndigits
no additional errors happen in the last step.
- The open() function now adds the filename to the exception when it
fails.
Built-in exceptions
-------------------
- New standard exceptions EnvironmentError and PosixError.
EnvironmentError is the base class for IOError and PosixError;
PosixError is the same as os.error. All this so that either exception
class can be instantiated with a third argument indicating a filename.
The built-in function open() and most os/posix functions that take a
filename argument now use this.
Built-in types
--------------
- List objects now have an experimental pop() method; l.pop() returns
and removes the last item; l.pop(i) returns and removes the item at
i. Also, the sort() method is faster again. Sorting is now also
safer: it is impossible for the sorting function to modify the list
while the sort is going on (which could cause core dumps).
- Changes to comparisons: numbers are now smaller than any other type.
This is done to prevent the circularity where [] < 0L < 1 < [] is
true. As a side effect, cmp(None, 0) is now positive instead of
negative. This *shouldn't* affect any working code, but I've found
that the change caused several "sleeping" bugs to become active, so
beware!
- Instance methods may now have other callable objects than just
Python functions as their im_func. Use new.instancemethod() or write
your own C code to create them; new.instancemethod() may be called
with None for the instance to create an unbound method.
- Assignment to __name__, __dict__ or __bases__ of a class object is
now allowed (with stringent type checks); also allow assignment to
__getattr__ etc. The cached values for __getattr__ etc. are
recomputed after such assignments (but not for derived classes :-( ).
- Allow assignment to some attributes of function objects: func_code,
func_defaults and func_doc / __doc__. (With type checks except for
__doc__ / func_doc .)
Python services
---------------
- New tests (in Lib/test): reperf.py (regular expression benchmark),
sortperf.py (list sorting benchmark), test_MimeWriter.py (test case
for the MimeWriter module).
- Generalized test/regrtest.py so that it is useful for testing other
packages.
- The ihooks.py module now understands package imports.
- In code.py, add a class that subsumes Fredrik Lundh's
PythonInterpreter class. The interact() function now uses this.
- In rlcompleter.py, in completer(), return None instead of raising an
IndexError when there are no more completions left.
- Fixed the marshal module to test for certain common kinds of invalid
input. (It's still not foolproof!)
- In the operator module, add an alias (now the preferred name)
"contains" for "sequenceincludes".
String Services
---------------
- In the string and strop modules, in the replace() function, treat an
empty pattern as an error (since it's not clear what was meant!).
- Some speedups to re.py, especially the string substitution and split
functions. Also added new function/method findall(), to find all
occurrences of a given substring.
- In cStringIO, add better argument type checking and support the
readonly 'closed' attribute (like regular files).
- In the struct module, unsigned 1-2 byte sized formats no longer
result in long integer values.
Miscellaneous services
----------------------
- In whrandom.py, added new method and function randrange(), same as
choice(range(start, stop, step)) but faster. This addresses the
problem that randint() was accidentally defined as taking an inclusive
range. Also, randint(a, b) is now redefined as randrange(a, b+1),
adding extra range and type checking to its arguments!
- Add some semi-thread-safety to random.gauss() (it used to be able to
crash when invoked from separate threads; now the worst it can do is
give a duplicate result occasionally).
- Some restructuring and generalization done to cmd.py.
- Major upgrade to ConfigParser.py; converted to using 're', added new
exceptions, support underscore in section header and option name. No
longer add 'name' option to every section; instead, add '__name__'.
- In getpass.py, don't use raw_input() to ask for the password -- we
don't want it to show up in the readline history! Also don't catch
interrupts (the try-finally already does all necessary cleanup).
Generic OS Services
-------------------
- New functions in os.py: makedirs(), removedirs(), renames(). New
variable: linesep (the line separator as found in binary files,
i.e. '\n' on Unix, '\r\n' on DOS/Windows, '\r' on Mac. Do *not* use
this with files opened in (default) text mode; the line separator used
will always be '\n'!
- Changes to the 'os.path' submodule of os.py: added getsize(),
getmtime(), getatime() -- these fetch the most popular items from the
stat return tuple.
- In the time module, add strptime(), if it exists. (This parses a
time according to a format -- the inverse of strftime().) Also,
remove the call to mktime() from strftime() -- it messed up the
formatting of some non-local times.
- In the socket module, added a new function gethostbyname_ex().
Also, don't use #ifdef to test for some symbols that are enums on some
platforms (and should exist everywhere).
Optional OS Services
--------------------
- Some fixes to gzip.py. In particular, the readlines() method now
returns the lines *with* trailing newline characters, like readlines()
of regular file objects. Also, it didn't work together with cPickle;
fixed that.
- In whichdb.py, support byte-swapped dbhash (bsddb) files.
- In anydbm.py, look at the type of an existing database to determine
which module to use to open it. (The anydbm.error exception is now a
tuple.)
Unix Services
-------------
- In the termios module, in tcsetattr(), initialize the structure vy
calling tcgetattr().
- Added some of the "wait status inspection" macros as functions to
the posix module (and thus to the os module): WEXITSTATUS(),
WIFEXITED(), WIFSIGNALED(), WIFSTOPPED(), WSTOPSIG(), WTERMSIG().
- In the syslog module, make the default facility more intuitive
(matching the docs).
Debugger
--------
- In pdb.py, support for setting breaks on files/modules that haven't
been loaded yet.
Internet Protocols and Support
------------------------------
- Changes in urllib.py; sped up unquote() and quote(). Fixed an
obscure bug in quote_plus(). Added urlencode(dict) -- convenience
function for sending a POST request with urlopen(). Use the getpass
module to ask for a password. Rewrote the (test) main program so that
when used as a script, it can retrieve one or more URLs to stdout.
Use -t to run the self-test. Made the proxy code work again.
- In cgi.py, treat "HEAD" the same as "GET", so that CGI scripts don't
fail when someone asks for their HEAD. Also, for POST, set the
default content-type to application/x-www-form-urlencoded. Also, in
FieldStorage.__init__(), when method='GET', always get the query
string from environ['QUERY_STRING'] or sys.argv[1] -- ignore an
explicitly passed in fp.
- The smtplib.py module now supports ESMTP and has improved standard
compliance, for picky servers.
- Improved imaplib.py.
- Fixed UDP support in SocketServer.py (it never worked).
- Fixed a small bug in CGIHTTPServer.py.
Internet Data handling
----------------------
- In rfc822.py, add a new class AddressList. Also support a new
overridable method, isheader(). Also add a get() method similar to
dictionaries (and make getheader() an alias for it). Also, be smarter
about seekable (test whether fp.tell() works) and test for presence of
unread() method before trying seeks.
- In sgmllib.py, restore the call to report_unbalanced() that was lost
long ago. Also some other improvements: handle <? processing
instructions >, allow . and - in entity names, and allow \r\n as line
separator.
- Some restructuring and generalization done to multifile.py; support
a 'seekable' flag.
Restricted Execution
--------------------
- Improvements to rexec.py: package support; support a (minimal)
sys.exc_info(). Also made the (test) main program a bit fancier (you
can now use it to run arbitrary Python scripts in restricted mode).
Tkinter
-------
- On Unix, Tkinter can now safely be used from a multi-threaded
application. (Formerly, no threads would make progress while
Tkinter's mainloop() was active, because it didn't release the Python
interpreter lock.) Unfortunately, on Windows, threads other than the
main thread should not call update() or update_idletasks() because
this will deadlock the application.
- An interactive interpreter that uses readline and Tkinter no longer
uses up all available CPU time.
- Even if readline is not used, Tk windows created in an interactive
interpreter now get continuously updated. (This even works in Windows
as long as you don't hit a key.)
- New demos in Demo/tkinter/guido/: brownian.py, redemo.py, switch.py.
- No longer register Tcl_finalize() as a low-level exit handler. It
may call back into Python, and that's a bad idea.
- Allow binding of Tcl commands (given as a string).
- Some minor speedups; replace explicitly coded getint() with int() in
most places.
- In FileDialog.py, remember the directory of the selected file, if
given.
- Change the names of all methods in the Wm class: they are now
wm_title(), etc. The old names (title() etc.) are still defined as
aliases.
- Add a new method of interpreter objects, interpaddr(). This returns
the address of the Tcl interpreter object, as an integer. Not very
useful for the Python programmer, but this can be called by another C
extension that needs to make calls into the Tcl/Tk C API and needs to
get the address of the Tcl interpreter object. A simple cast of the
return value to (Tcl_Interp *) will do the trick.
Windows General
---------------
- Don't insist on proper case for module source files if the filename
is all uppercase (e.g. FOO.PY now matches foo; but FOO.py still
doesn't). This should address problems with this feature on
oldfashioned filesystems (Novell servers?).
Windows Library
---------------
- os.environ is now all uppercase, but accesses are case insensitive,
and the putenv() calls made as a side effect of changing os.environ
are case preserving.
- Removed samefile(), sameopenfile(), samestat() from os.path (aka
ntpath.py) -- these cannot be made to work reliably (at least I
wouldn't know how).
- Fixed os.pipe() so that it returns file descriptors acceptable to
os.read() and os.write() (like it does on Unix), rather than Windows
file handles.
- Added a table of WSA error codes to socket.py.
- In the select module, put the (huge) file descriptor arrays on the
heap.
- The getpass module now raises KeyboardInterrupt when it sees ^C.
- In mailbox.py, fix tell/seek when using files opened in text mode.
- In rfc822.py, fix tell/seek when using files opened in text mode.
- In the msvcrt extension module, release the interpreter lock for
calls that may block: _locking(), _getch(), _getche(). Also fix a
bogus error return when open_osfhandle() doesn't have the right
argument list.
Windows Installer
-----------------
- The registry key used is now "1.5" instead of "1.5.x" -- so future
versions of 1.5 and Mark Hammond's win32all installer don't need to be
resynchronized.
Windows Tools
-------------
- Several improvements to freeze specifically for Windows.
Windows Build Procedure
-----------------------
- The VC++ project files and the WISE installer have been moved to the
PCbuild subdirectory, so they are distributed in the same subdirectory
where they must be used. This avoids confusion.
- New project files for Windows 3.1 port by Jim Ahlstrom.
- Got rid of the obsolete subdirectory PC/setup_nt/.
- The projects now use distinct filenames for the .exe, .dll, .lib and
.pyd files built in debug mode (by appending "_d" to the base name,
before the extension). This makes it easier to switch between the two
and get the right versions. There's a pragma in config.h that directs
the linker to include the appropriate .lib file (so python15.lib no
longer needs to be explicit in your project).
- The installer now installs more files (e.g. config.h). The idea is
that you shouldn't need the source distribution if you want build your
own extensions in C or C++.
Tools and Demos
---------------
- New script nm2def.py by Marc-Andre Lemburg, to construct
PC/python_nt.def automatically (some hand editing still required).
- New tool ndiff.py: Tim Peters' text diffing tool.
- Various and sundry improvements to the freeze script.
- The script texi2html.py (which was part of the Doc tree but is no
longer used there) has been moved to the Tools/scripts subdirectory.
- Some generalizations in the webchecker code. There's now a
primnitive gui for websucker.py: wsgui.py. (In Tools/webchecker/.)
- The ftpmirror.py script now handles symbolic links properly, and
also files with multiple spaces in their names.
- The 1.5.1 tabnanny.py suffers an assert error if fed a script whose
last line is both indented and lacks a newline. This is now fixed.
Python/C API
------------
- Added missing prototypes for PyEval_CallFunction() and
PyEval_CallMethod().
- New macro PyList_SET_ITEM().
- New macros to access object members for PyFunction, PyCFunction
objects.
- New APIs PyImport_AppendInittab() an PyImport_ExtendInittab() to
dynamically add one or many entries to the table of built-in modules.
- New macro Py_InitModule3(name, methods, doc) which calls
Py_InitModule4() with appropriate arguments. (The -4 variant requires
you to pass an obscure version number constant which is always the same.)
- New APIs PySys_WriteStdout() and PySys_WriteStderr() to write to
sys.stdout or sys.stderr using a printf-like interface. (Used in
_tkinter.c, for example.)
- New APIs for conversion between Python longs and C 'long long' if
your compiler supports it.
- PySequence_In() is now called PySequence_Contains().
(PySequence_In() is still supported for b/w compatibility; it is
declared obsolete because its argument order is confusing.)
- PyDict_GetItem() and PyDict_GetItemString() are changed so that they
*never* raise an exception -- (even if the hash() fails, simply clear
the error). This was necessary because there is lots of code out
there that already assumes this.
- Changes to PySequence_Tuple() and PySequence_List() to use the
length of a sequence only as a hint -- if an IndexError happens
earlier, take that. (Formerly, this was considered an error.)
- Reformatted abstract.c to give it a more familiar "look" and fixed
many error checking bugs.
- Add NULL pointer checks to all calls of a C function through a type
object and extensions (e.g. nb_add).
- The code that initializes sys.path now calls Py_GetPythonHome()
instead of getenv("PYTHONHOME"). This, together with the new API
Py_SetPythonHome(), makes it easier for embedding applications to
change the notion of Python's "home" directory (where the libraries
etc. are sought).
- Fixed a very old bug in the parsing of "O?" format specifiers.
======================================================================
========================================
==> Release 1.5.1 (October 31, 1998) <==
========================================
From 1.5 to 1.5.1
=================
General
-------
- The documentation is now unbundled. It has also been extensively
modified (mostly to implement a new and more uniform formatting
style). We figure that most people will prefer to download one of the
preformatted documentation sets (HTML, PostScript or PDF) and that
only a minority have a need for the LaTeX or FrameMaker sources. Of
course, the unbundled documentation sources still released -- just not
in the same archive file, and perhaps not on the same date.
- All bugs noted on the errors page (and many unnoted) are fixed. All
new bugs take their places.
- No longer a core dump when attempting to print (or repr(), or str())
a list or dictionary that contains an instance of itself; instead, the
recursive entry is printed as [...] or {...}. See Py_ReprEnter() and
Py_ReprLeave() below. Comparisons of such objects still go beserk,
since this requires a different kind of fix; fortunately, this is a
less common scenario in practice.
Syntax change
-------------
- The raise statement can now be used without arguments, to re-raise
a previously set exception. This should be used after catching an
exception with an except clause only, either in the except clause or
later in the same function.
Import and module handling
--------------------------
- The implementation of import has changed to use a mutex (when
threading is supported). This means that when two threads
simultaneously import the same module, the import statements are
serialized. Recursive imports are not affected.
- Rewrote the finalization code almost completely, to be much more
careful with the order in which modules are destroyed. Destructors
will now generally be able to reference built-in names such as None
without trouble.
- Case-insensitive platforms such as Mac and Windows require the case
of a module's filename to match the case of the module name as
specified in the import statement (see below).
- The code for figuring out the default path now distinguishes between
files, modules, executable files, and directories. When expecting a
module, we also look for the .pyc or .pyo file.
Parser/tokenizer changes
------------------------
- The tokenizer can now warn you when your source code mixes tabs and
spaces for indentation in a manner that depends on how much a tab is
worth in spaces. Use "python -t" or "python -v" to enable this
option. Use "python -tt" to turn the warnings into errors. (See also
tabnanny.py and tabpolice.py below.)
- Return unsigned characters from tok_nextc(), so '\377' isn't
mistaken for an EOF character.
- Fixed two pernicious bugs in the tokenizer that only affected AIX.
One was actually a general bug that was triggered by AIX's smaller I/O
buffer size. The other was a bug in the AIX optimizer's loop
unrolling code; swapping two statements made the problem go away.
Tools, demos and miscellaneous files
------------------------------------
- There's a new version of Misc/python-mode.el (the Emacs mode for
Python) which is much smarter about guessing the indentation style
used in a particular file. Lots of other cool features too!
- There are two new tools in Tools/scripts: tabnanny.py and
tabpolice.py, implementing two different ways of checking whether a
file uses indentation in a way that is sensitive to the interpretation
of a tab. The preferred module is tabnanny.py (by Tim Peters).
- Some new demo programs:
Demo/tkinter/guido/paint.py -- Dave Mitchell
Demo/sockets/unixserver.py -- Piet van Oostrum
- Much better freeze support. The freeze script can now freeze
hierarchical module names (with a corresponding change to import.c),
and has a few extra options (e.g. to suppress freezing specific
modules). It also does much more on Windows NT.
- Version 1.0 of the faq wizard is included (only very small changes
since version 0.9.0).
- New feature for the ftpmirror script: when removing local files
(i.e., only when -r is used), do a recursive delete.
Configuring and building Python
-------------------------------
- Get rid of the check for -linet -- recent Sequent Dynix systems don't
need this any more and apparently it screws up their configuration.
- Some changes because gcc on SGI doesn't support '-all'.
- Changed the build rules to use $(LIBRARY) instead of
-L.. -lpython$(VERSION)
since the latter trips up the SunOS 4.1.x linker (sigh).
- Fix the bug where the '# dgux is broken' comment in the Makefile
tripped over Make on some platforms.
- Changes for AIX: install the python.exp file; properly use
$(srcdir); the makexp_aix script now removes C++ entries of the form
Class::method.
- Deleted some Makefile targets only used by the (long obsolete)
gMakefile hacks.
Extension modules
-----------------
- Performance and threading improvements to the socket and bsddb
modules, by Christopher Lindblad of Infoseek.
- Added operator.__not__ and operator.not_.
- In the thread module, when a thread exits due to an unhandled
exception, don't store the exception information in sys.last_*; it
prevents proper calling of destructors of local variables.
- Fixed a number of small bugs in the cPickle module.
- Changed find() and rfind() in the strop module so that
find("x","",2) returns -1, matching the implementation in string.py.
- In the time module, be more careful with the result of ctime(), and
test for HAVE_MKTIME before usinmg mktime().
- Doc strings contributed by Mitch Chapman to the termios, pwd, gdbm
modules.
- Added the LOG_SYSLOG constant to the syslog module, if defined.
Standard library modules
------------------------
- All standard library modules have been converted to an indentation
style using either only tabs or only spaces -- never a mixture -- if
they weren't already consistent according to tabnanny. This means
that the new -t option (see above) won't complain about standard
library modules.
- New standard library modules:
threading -- GvR and the thread-sig
Java style thread objects -- USE THIS!!!
getpass -- Piers Lauder
simple utilities to prompt for a password and to
retrieve the current username
imaplib -- Piers Lauder
interface for the IMAP4 protocol
poplib -- David Ascher, Piers Lauder
interface for the POP3 protocol
smtplib -- Dragon De Monsyne
interface for the SMTP protocol
- Some obsolete modules moved to a separate directory (Lib/lib-old)
which is *not* in the default module search path:
Para
addpack
codehack
fmt
lockfile
newdir
ni
rand
tb
- New version of the PCRE code (Perl Compatible Regular Expressions --
the re module and the supporting pcre extension) by Andrew Kuchling.
Incompatible new feature in re.sub(): the handling of escapes in the
replacement string has changed.
- Interface change in the copy module: a __deepcopy__ method is now
called with the memo dictionary as an argument.
- Feature change in the tokenize module: differentiate between NEWLINE
token (an official newline) and NL token (a newline that the grammar
ignores).
- Several bugfixes to the urllib module. It is now truly thread-safe,
and several bugs and a portability problem have been fixed. New
features, all due to Sjoerd Mullender: When creating a temporary file,
it gives it an appropriate suffix. Support the "data:" URL scheme.
The open() method uses the tempcache.
- New version of the xmllib module (this time with a test suite!) by
Sjoerd Mullender.
- Added debugging code to the telnetlib module, to be able to trace
the actual traffic.
- In the rfc822 module, added support for deleting a header (still no
support for adding headers, though). Also fixed a bug where an
illegal address would cause a crash in getrouteaddr(), fixed a
sign reversal in mktime_tz(), and use the local timezone by default
(the latter two due to Bill van Melle).
- The normpath() function in the dospath and ntpath modules no longer
does case normalization -- for that, use the separate function
normcase() (which always existed); normcase() has been sped up and
fixed (it was the cause of a crash in Mark Hammond's installer in
certain locales).
- New command supported by the ftplib module: rmd(); also fixed some
minor bugs.
- The profile module now uses a different timer function by default --
time.clock() is generally better than os.times(). This makes it work
better on Windows NT, too.
- The tempfile module now recovers when os.getcwd() raises an
exception.
- Fixed some bugs in the random module; gauss() was subtly wrong, and
vonmisesvariate() should return a full circle. Courtesy Mike Miller,
Lambert Meertens (gauss()), and Magnus Kessler (vonmisesvariate()).
- Better default seed in the whrandom module, courtesy Andrew Kuchling.
- Fix slow close() in shelve module.
- The Unix mailbox class in the mailbox module is now more robust when
a line begins with the string "From " but is definitely not the start
of a new message. The pattern used can be changed by overriding a
method or class variable.
- Added a rmtree() function to the copy module.
- Fixed several typos in the pickle module. Also fixed problems when
unpickling in restricted execution environments.
- Added docstrings and fixed a typo in the py_compile and compileall
modules. At Mark Hammond's repeated request, py_compile now append a
newline to the source if it needs one. Both modules support an extra
parameter to specify the purported source filename (to be used in
error messages).
- Some performance tweaks by Jeremy Hylton to the gzip module.
- Fixed a bug in the merge order of dictionaries in the ConfigParser
module. Courtesy Barry Warsaw.
- In the multifile module, support the optional second parameter to
seek() when possible.
- Several fixes to the gopherlib module by Lars Marius Garshol. Also,
urlparse now correctly handles Gopher URLs with query strings.
- Fixed a tiny bug in format_exception() in the traceback module.
Also rewrite tb_lineno() to be compatible with JPython (and not
disturb the current exception!); by Jim Hugunin.
- The httplib module is more robust when servers send a short response
-- courtesy Tim O'Malley.
Tkinter and friends
-------------------
- Various typos and bugs fixed.
- New module Tkdnd implements a drag-and-drop protocol (within one
application only).
- The event_*() widget methods have been restructured slightly -- they
no longer use the default root.
- The interfaces for the bind*() and unbind() widget methods have been
redesigned; the bind*() methods now return the name of the Tcl command
created for the callback, and this can be passed as a optional
argument to unbind() in order to delete the command (normally, such
commands are automatically unbound when the widget is destroyed, but
for some applications this isn't enough).
- Variable objects now have trace methods to interface to Tcl's
variable tracing facilities.
- Image objects now have an optional keyword argument, 'master', to
specify a widget (tree) to which they belong. The image_names() and
image_types() calls are now also widget methods.
- There's a new global call, Tkinter.NoDefaultRoot(), which disables
all use of the default root by the Tkinter library. This is useful to
debug applications that are in the process of being converted from
relying on the default root to explicit specification of the root
widget.
- The 'exit' command is deleted from the Tcl interpreter, since it
provided a loophole by which one could (accidentally) exit the Python
interpreter without invoking any cleanup code.
- Tcl_Finalize() is now registered as a Python low-level exit handle,
so Tcl will be finalized when Python exits.
The Python/C API
----------------
- New function PyThreadState_GetDict() returns a per-thread dictionary
intended for storing thread-local global variables.
- New functions Py_ReprEnter() and Py_ReprLeave() use the per-thread
dictionary to allow recursive container types to detect recursion in
their repr(), str() and print implementations.
- New function PyObject_Not(x) calculates (not x) according to Python's
standard rules (basically, it negates the outcome PyObject_IsTrue(x).
- New function _PyModule_Clear(), which clears a module's dictionary
carefully without removing the __builtins__ entry. This is implied
when a module object is deallocated (this used to clear the dictionary
completely).
- New function PyImport_ExecCodeModuleEx(), which extends
PyImport_ExecCodeModule() by adding an extra parameter to pass it the
true file.
- New functions Py_GetPythonHome() and Py_SetPythonHome(), intended to
allow embedded applications to force a different value for PYTHONHOME.
- New global flag Py_FrozenFlag is set when this is a "frozen" Python
binary; it suppresses warnings about not being able to find the
standard library directories.
- New global flag Py_TabcheckFlag is incremented by the -t option and
causes the tokenizer to issue warnings or errors about inconsistent
mixing of tabs and spaces for indentation.
Miscellaneous minor changes and bug fixes
-----------------------------------------
- Improved the error message when an attribute of an attribute-less
object is requested -- include the name of the attribute and the type
of the object in the message.
- Sped up int(), long(), float() a bit.
- Fixed a bug in list.sort() that would occasionally dump core.
- Fixed a bug in PyNumber_Power() that caused numeric arrays to fail
when taken tothe real power.
- Fixed a number of bugs in the file reading code, at least one of
which could cause a core dump on NT, and one of which would
occasionally cause file.read() to return less than the full contents
of the file.
- Performance hack by Vladimir Marangozov for stack frame creation.
- Make sure setvbuf() isn't used unless HAVE_SETVBUF is defined.
Windows 95/NT
-------------
- The .lib files are now part of the distribution; they are collected
in the subdirectory "libs" of the installation directory.
- The extension modules (.pyd files) are now collected in a separate
subdirectory of the installation directory named "DLLs".
- The case of a module's filename must now match the case of the
module name as specified in the import statement. This is an
experimental feature -- if it turns out to break in too many
situations, it will be removed (or disabled by default) in the future.
It can be disabled on a per-case basis by setting the environment
variable PYTHONCASEOK (to any value).
======================================================================
=====================================
==> Release 1.5 (January 3, 1998) <==
=====================================
From 1.5b2 to 1.5
=================
- Newly documentated module: BaseHTTPServer.py, thanks to Greg Stein.
- Added doc strings to string.py, stropmodule.c, structmodule.c,
thanks to Charles Waldman.
- Many nits fixed in the manuals, thanks to Fred Drake and many others
(especially Rob Hooft and Andrew Kuchling). The HTML version now uses
HTML markup instead of inline GIF images for tables; only two images
are left (for obsure bits of math). The index of the HTML version has
also been much improved. Finally, it is once again possible to
generate an Emacs info file from the library manual (but I don't
commit to supporting this in future versions).
- New module: telnetlib.py (a simple telnet client library).
- New tool: Tools/versioncheck/, by Jack Jansen.
- Ported zlibmodule.c and bsddbmodule.c to NT; The project file for MS
DevStudio 5.0 now includes new subprojects to build the zlib and bsddb
extension modules.
- Many small changes again to Tkinter.py -- mostly bugfixes and adding
missing routines. Thanks to Greg McFarlane for reporting a bunch of
problems and proofreading my fixes.
- The re module and its documentation are up to date with the latest
version released to the string-sig (Dec. 22).
- Stop test_grp.py from failing when the /etc/group file is empty
(yes, this happens!).
- Fix bug in integer conversion (mystrtoul.c) that caused
4294967296==0 to be true!
- The VC++ 4.2 project file should be complete again.
- In tempfile.py, use a better template on NT, and add a new optional
argument "suffix" with default "" to specify a specific extension for
the temporary filename (needed sometimes on NT but perhaps also handy
elsewhere).
- Fixed some bugs in the FAQ wizard, and converted it to use re
instead of regex.
- Fixed a mysteriously undetected error in dlmodule.c (it was using a
totally bogus routine name to raise an exception).
- Fixed bug in import.c which wasn't using the new "dos-8x3" name yet.
- Hopefully harmless changes to the build process to support shared
libraries on DG/UX. This adds a target to create
libpython$(VERSION).so; however this target is *only* for DG/UX.
- Fixed a bug in the new format string error checking in getargs.c.
- A simple fix for infinite recursion when printing __builtins__:
reset '_' to None before printing and set it to the printed variable
*after* printing (and only when printing is successful).
- Fixed lib-tk/SimpleDialog.py to keep the dialog visible even if the
parent window is not (Skip Montanaro).
- Fixed the two most annoying problems with ftp URLs in
urllib.urlopen(); an empty file now correctly raises an error, and it
is no longer required to explicitly close the returned "file" object
before opening another ftp URL to the same host and directory.
======================================================================
From 1.5b1 to 1.5b2
===================
- Fixed a bug in cPickle.c that caused it to crash right away because
the version string had a different format.
- Changes in pickle.py and cPickle.c: when unpickling an instance of a
class that doesn't define the __getinitargs__() method, the __init__()
constructor is no longer called. This makes a much larger group of
classes picklable by default, but may occasionally change semantics.
To force calling __init__() on unpickling, define a __getinitargs__()
method. Other changes too, in particular cPickle now handles classes
defined in packages correctly. The same change applies to copying
instances with copy.py. The cPickle.c changes and some pickle.py
changes are courtesy Jim Fulton.
- Locale support in he "re" (Perl regular expressions) module. Use
the flag re.L (or re.LOCALE) to enable locale-specific matching
rules for \w and \b. The in-line syntax for this flag is (?L).
- The built-in function isinstance(x, y) now also succeeds when y is
a type object and type(x) is y.
- repr() and str() of class and instance objects now reflect the
package/module in which the class is defined.
- Module "ni" has been removed. (If you really need it, it's been
renamed to "ni1". Let me know if this causes any problems for you.
Package authors are encouraged to write __init__.py files that
support both ni and 1.5 package support, so the same version can be
used with Python 1.4 as well as 1.5.)
- The thread module is now automatically included when threads are
configured. (You must remove it from your existing Setup file,
since it is now in its own Setup.thread file.)
- New command line option "-x" to skip the first line of the script;
handy to make executable scripts on non-Unix platforms.
- In importdl.c, add the RTLD_GLOBAL to the dlopen() flags. I
haven't checked how this affects things, but it should make symbols
in one shared library available to the next one.
- The Windows installer now installs in the "Program Files" folder on
the proper volume by default.
- The Windows configuration adds a new main program, "pythonw", and
registers a new extension, ".pyw" that invokes this. This is a
pstandard Python interpreter that does not pop up a console window;
handy for pure Tkinter applications. All output to the original
stdout and stderr is lost; reading from the original stdin yields
EOF. Also, both python.exe and pythonw.exe now have a pretty icon
(a green snake in a box, courtesy Mark Hammond).
- Lots of improvements to emacs-mode.el again. See Barry's web page:
http://www.python.org/ftp/emacs/pmdetails.html.
- Lots of improvements and additions to the library reference manual;
many by Fred Drake.
- Doc strings for the following modules: rfc822.py, posixpath.py,
ntpath.py, httplib.py. Thanks to Mitch Chapman and Charles Waldman.
- Some more regression testing.
- An optional 4th (maxsplit) argument to strop.replace().
- Fixed handling of maxsplit in string.splitfields().
- Tweaked os.environ so it can be pickled and copied.
- The portability problems caused by indented preprocessor commands
and C++ style comments should be gone now.
- In random.py, added Pareto and Weibull distributions.
- The crypt module is now disabled in Modules/Setup.in by default; it
is rarely needed and causes errors on some systems where users often
don't know how to deal with those.
- Some improvements to the _tkinter build line suggested by Case Roole.
- A full suite of platform specific files for NetBSD 1.x, submitted by
Anders Andersen.
- New Solaris specific header STROPTS.py.
- Moved a confusing occurrence of *shared* from the comments in
Modules/Setup.in (people would enable this one instead of the real
one, and get disappointing results).
- Changed the default mode for directories to be group-writable when
the installation process creates them.
- Check for pthread support in "-l_r" for FreeBSD/NetBSD, and support
shared libraries for both.
- Support FreeBSD and NetBSD in posixfile.py.
- Support for the "event" command, new in Tk 4.2. By Case Roole.
- Add Tix_SafeInit() support to tkappinit.c.
- Various bugs fixed in "re.py" and "pcre.c".
- Fixed a bug (broken use of the syntax table) in the old "regexpr.c".
- In frozenmain.c, stdin is made unbuffered too when PYTHONUNBUFFERED
is set.
- Provide default blocksize for retrbinary in ftplib.py (Skip
Montanaro).
- In NT, pick the username up from different places in user.py (Jeff
Bauer).
- Patch to urlparse.urljoin() for ".." and "..#1", Marc Lemburg.
- Many small improvements to Jeff Rush' OS/2 support.
- ospath.py is gone; it's been obsolete for so many years now...
- The reference manual is now set up to prepare better HTML (still
using webmaker, alas).
- Add special handling to /Tools/freeze for Python modules that are
imported implicitly by the Python runtime: 'site' and 'exceptions'.
- Tools/faqwiz 0.8.3 -- add an option to suppress URL processing
inside <PRE>, by "Scott".
- Added ConfigParser.py, a generic parser for sectioned configuration
files.
- In _localemodule.c, LC_MESSAGES is not always defined; put it
between #ifdefs.
- Typo in resource.c: RUSAGE_CHILDERN -> RUSAGE_CHILDREN.
- Demo/scripts/newslist.py: Fix the way the version number is gotten
out of the RCS revision.
- PyArg_Parse[Tuple] now explicitly check for bad characters at the
end of the format string.
- Revamped PC/example_nt to support VC++ 5.x.
- <listobject>.sort() now uses a modified quicksort by Raymund Galvin,
after studying the GNU libg++ quicksort. This should be much faster
if there are lots of duplicates, and otherwise at least as good.
- Added "uue" as an alias for "uuencode" to mimetools.py. (Hm, the
uudecode bug where it complaints about trailing garbage is still there
:-( ).
- pickle.py requires integers in text mode to be in decimal notation
(it used to accept octal and hex, even though it would only generate
decimal numbers).
- In string.atof(), don't fail when the "re" module is unavailable.
Plug the ensueing security leak by supplying an empty __builtins__
directory to eval().
- A bunch of small fixes and improvements to Tkinter.py.
- Fixed a buffer overrun in PC/getpathp.c.
======================================================================
From 1.5a4 to 1.5b1
===================
- The Windows NT/95 installer now includes full HTML of all manuals.
It also has a checkbox that lets you decide whether to install the
interpreter and library. The WISE installer script for the installer
is included in the source tree as PC/python15.wse, and so are the
icons used for Python files. The config.c file for the Windows build
is now complete with the pcre module.
- sys.ps1 and sys.ps2 can now arbitrary objects; their str() is
evaluated for the prompt.
- The reference manual is brought up to date (more or less -- it still
needs work, e.g. in the area of package import).
- The icons used by latex2html are now included in the Doc
subdirectory (mostly so that tarring up the HTML files can be fully
automated). A simple index.html is also added to Doc (it only works
after you have successfully run latex2html).
- For all you would-be proselytizers out there: a new version of
Misc/BLURB describes Python more concisely, and Misc/comparisons
compares Python to several other languages. Misc/BLURB.WINDOWS
contains a blurb specifically aimed at Windows programmers (by Mark
Hammond).
- A new version of the Python mode for Emacs is included as
Misc/python-mode.el. There are too many new features to list here.
See http://www.python.org/ftp/emacs/pmdetails.html for more info.
- New module fileinput makes iterating over the lines of a list of
files easier. (This still needs some more thinking to make it more
extensible.)
- There's full OS/2 support, courtesy Jeff Rush. To build the OS/2
version, see PC/readme.txt and PC/os2vacpp. This is for IBM's Visual
Age C++ compiler. I expect that Jeff will also provide a binary
release for this platform.
- On Linux, the configure script now uses '-Xlinker -export-dynamic'
instead of '-rdynamic' to link the main program so that it exports its
symbols to shared libraries it loads dynamically. I hope this doesn't
break on older Linux versions; it is needed for mklinux and appears to
work on Linux 2.0.30.
- Some Tkinter resstructuring: the geometry methods that apply to a
master are now properly usable on toplevel master widgets. There's a
new (internal) widget class, BaseWidget. New, longer "official" names
for the geometry manager methods have been added,
e.g. "grid_columnconfigure()" instead of "columnconfigure()". The old
shorter names still work, and where there's ambiguity, pack wins over
place wins over grid. Also, the bind_class method now returns its
value.
- New, RFC-822 conformant parsing of email addresses and address lists
in the rfc822 module, courtesy Ben Escoto.
- New, revamped tkappinit.c with support for popular packages (PIL,
TIX, BLT, TOGL). For the last three, you need to execute the Tcl
command "load {} Tix" (or Blt, or Togl) to gain access to them.
The Modules/Setup line for the _tkinter module has been rewritten
using the cool line-breaking feature of most Bourne shells.
- New socket method connect_ex() returns the error code from connect()
instead of raising an exception on errors; this makes the logic
required for asynchronous connects simpler and more efficient.
- New "locale" module with (still experimental) interface to the
standard C library locale interface, courtesy Martin von Loewis. This
does not repeat my mistake in 1.5a4 of always calling
setlocale(LC_ALL, ""). In fact, we've pretty much decided that
Python's standard numerical formatting operations should always use
the conventions for the C locale; the locale module contains utility
functions to format numbers according to the user specified locale.
(All this is accomplished by an explicit call to setlocale(LC_NUMERIC,
"C") after locale-changing calls.) See the library manual. (Alas, the
promised changes to the "re" module for locale support have not been
materialized yet. If you care, volunteer!)
- Memory leak plugged in Py_BuildValue when building a dictionary.
- Shared modules can now live inside packages (hierarchical module
namespaces). No changes to the shared module itself are needed.
- Improved policy for __builtins__: this is a module in __main__ and a
dictionary everywhere else.
- Python no longer catches SIGHUP and SIGTERM by default. This was
impossible to get right in the light of thread contexts. If you want
your program to clean up when a signal happens, use the signal module
to set up your own signal handler.
- New Python/C API PyNumber_CoerceEx() does not return an exception
when no coercion is possible. This is used to fix a problem where
comparing incompatible numbers for equality would raise an exception
rather than return false as in Python 1.4 -- it once again will return
false.
- The errno module is changed again -- the table of error messages
(errorstr) is removed. Instead, you can use os.strerror(). This
removes redundance and a potential locale dependency.
- New module xmllib, to parse XML files. By Sjoerd Mullender.
- New C API PyOS_AfterFork() is called after fork() in posixmodule.c.
It resets the signal module's notion of what the current process ID
and thread are, so that signal handlers will work after (and across)
calls to os.fork().
- Fixed most occurrences of fatal errors due to missing thread state.
- For vgrind (a flexible source pretty printer) fans, there's a simple
Python definition in Misc/vgrindefs, courtesy Neale Pickett.
- Fixed memory leak in exec statement.
- The test.pystone module has a new function, pystones(loops=LOOPS),
which returns a (benchtime, stones) tuple. The main() function now
calls this and prints the report.
- Package directories now *require* the presence of an __init__.py (or
__init__.pyc) file before they are considered as packages. This is
done to prevent accidental subdirectories with common names from
overriding modules with the same name.
- Fixed some strange exceptions in __del__ methods in library modules
(e.g. urllib). This happens because the builtin names are already
deleted by the time __del__ is called. The solution (a hack, but it
works) is to set some instance variables to 0 instead of None.
- The table of built-in module initializers is replaced by a pointer
variable. This makes it possible to switch to a different table at
run time, e.g. when a collection of modules is loaded from a shared
library. (No example code of how to do this is given, but it is
possible.) The table is still there of course, its name prefixed with
an underscore and used to initialize the pointer.
- The warning about a thread still having a frame now only happens in
verbose mode.
- Change the signal finialization so that it also resets the signal
handlers. After this has been called, our signal handlers are no
longer active!
- New version of tokenize.py (by Ka-Ping Yee) recognizes raw string
literals. There's now also a test fort this module.
- The copy module now also uses __dict__.update(state) instead of
going through individual attribute assignments, for class instances
without a __setstate__ method.
- New module reconvert translates old-style (regex module) regular
expressions to new-style (re module, Perl-style) regular expressions.
- Most modules that used to use the regex module now use the re
module. The grep module has a new pgrep() function which uses
Perl-style regular expressions.
- The (very old, backwards compatibility) regexp.py module has been
deleted.
- Restricted execution (rexec): added the pcre module (support for the
re module) to the list of trusted extension modules.
- New version of Jim Fulton's CObject object type, adds
PyCObject_FromVoidPtrAndDesc() and PyCObject_GetDesc() APIs.
- Some patches to Lee Busby's fpectl mods that accidentally didn't
make it into 1.5a4.
- In the string module, add an optional 4th argument to count(),
matching find() etc.
- Patch for the nntplib module by Charles Waldman to add optional user
and password arguments to NNTP.__init__(), for nntp servers that need
them.
- The str() function for class objects now returns
"modulename.classname" instead of returning the same as repr().
- The parsing of \xXX escapes no longer relies on sscanf().
- The "sharedmodules" subdirectory of the installation is renamed to
"lib-dynload". (You may have to edit your Modules/Setup file to fix
this in an existing installation!)
- Fixed Don Beaudry's mess-up with the OPT test in the configure
script. Certain SGI platforms will still issue a warning for each
compile; there's not much I can do about this since the compiler's
exit status doesn't indicate that I was using an obsolete option.
- Fixed Barry's mess-up with {}.get(), and added test cases for it.
- Shared libraries didn't quite work under AIX because of the change
in status of the GNU readline interface. Fix due to by Vladimir
Marangozov.
======================================================================
From 1.5a3 to 1.5a4
===================
- faqwiz.py: version 0.8; Recognize https:// as URL; <html>...</html>
feature; better install instructions; removed faqmain.py (which was an
older version).
- nntplib.py: Fixed some bugs reported by Lars Wirzenius (to Debian)
about the treatment of lines starting with '.'. Added a minimal test
function.
- struct module: ignore most whitespace in format strings.
- urllib.py: close the socket and temp file in URLopener.retrieve() so
that multiple retrievals using the same connection work.
- All standard exceptions are now classes by default; use -X to make
them strings (for backward compatibility only).
- There's a new standard exception hierarchy, defined in the standard
library module exceptions.py (which you never need to import
explicitly). See
http://grail.cnri.reston.va.us/python/essays/stdexceptions.html for
more info.
- Three new C API functions:
- int PyErr_GivenExceptionMatches(obj1, obj2)
Returns 1 if obj1 and obj2 are the same object, or if obj1 is an
instance of type obj2, or of a class derived from obj2
- int PyErr_ExceptionMatches(obj)
Higher level wrapper around PyErr_GivenExceptionMatches() which uses
PyErr_Occurred() as obj1. This will be the more commonly called
function.
- void PyErr_NormalizeException(typeptr, valptr, tbptr)
Normalizes exceptions, and places the normalized values in the
arguments. If type is not a class, this does nothing. If type is a
class, then it makes sure that value is an instance of the class by:
1. if instance is of the type, or a class derived from type, it does
nothing.
2. otherwise it instantiates the class, using the value as an
argument. If value is None, it uses an empty arg tuple, and if
the value is a tuple, it uses just that.
- Another new C API function: PyErr_NewException() creates a new
exception class derived from Exception; when -X is given, it creates a
new string exception.
- core interpreter: remove the distinction between tuple and list
unpacking; allow an arbitrary sequence on the right hand side of any
unpack instruction. (UNPACK_LIST and UNPACK_TUPLE now do the same
thing, which should really be called UNPACK_SEQUENCE.)
- classes: Allow assignments to an instance's __dict__ or __class__,
so you can change ivars (including shared ivars -- shock horror) and
change classes dynamically. Also make the check on read-only
attributes of classes less draconic -- only the specials names
__dict__, __bases__, __name__ and __{get,set,del}attr__ can't be
assigned.
- Two new built-in functions: issubclass() and isinstance(). Both
take classes as their second arguments. The former takes a class as
the first argument and returns true iff first is second, or is a
subclass of second. The latter takes any object as the first argument
and returns true iff first is an instance of the second, or any
subclass of second.
- configure: Added configuration tests for presence of alarm(),
pause(), and getpwent().
- Doc/Makefile: changed latex2html targets.
- classes: Reverse the search order for the Don Beaudry hook so that
the first class with an applicable hook wins. Makes more sense.
- Changed the checks made in Py_Initialize() and Py_Finalize(). It is
now legal to call these more than once. The first call to
Py_Initialize() initializes, the first call to Py_Finalize()
finalizes. There's also a new API, Py_IsInitalized() which checks
whether we are already initialized (in case you want to leave things
as they were).
- Completely disable the declarations for malloc(), realloc() and
free(). Any 90's C compiler has these in header files, and the tests
to decide whether to suppress the declarations kept failing on some
platforms.
- *Before* (instead of after) signalmodule.o is added, remove both
intrcheck.o and sigcheck.o. This should get rid of warnings in ar or
ld on various systems.
- Added reop to PC/config.c
- configure: Decided to use -Aa -D_HPUX_SOURCE on HP-UX platforms.
Removed outdated HP-UX comments from README. Added Cray T3E comments.
- Various renames of statically defined functions that had name
conflicts on some systems, e.g. strndup (GNU libc), join (Cray),
roundup (sys/types.h).
- urllib.py: Interpret three slashes in file: URL as local file (for
Netscape on Windows/Mac).
- copy.py: Make sure the objects returned by __getinitargs__() are
kept alive (in the memo) to avoid a certain kind of nasty crash. (Not
easily reproducable because it requires a later call to
__getinitargs__() to return a tuple that happens to be allocated at
the same address.)
- Added definition of AR to toplevel Makefile. Renamed @buildno temp
file to buildno1.
- Moved Include/assert.h to Parser/assert.h, which seems to be the
only place where it's needed.
- Tweaked the dictionary lookup code again for some more speed
(Vladimir Marangozov).
- NT build: Changed the way python15.lib is included in the other
projects. Per Mark Hammond's suggestion, add it to the extra libs in
Settings instead of to the project's source files.
- regrtest.py: Change default verbosity so that there are only three
levels left: -q, default and -v. In default mode, the name of each
test is now printed. -v is the same as the old -vv. -q is more quiet
than the old default mode.
- Removed the old FAQ from the distribution. You now have to get it
from the web!
- Removed the PC/make_nt.in file from the distribution; it is no
longer needed.
- Changed the build sequence so that shared modules are built last.
This fixes things for AIX and doesn't hurt elsewhere.
- Improved test for GNU MP v1 in mpzmodule.c
- fileobject.c: ftell() on Linux discards all buffered data; changed
read() code to use lseek() instead to get the same effect
- configure.in, configure, importdl.c: NeXT sharedlib fixes
- tupleobject.c: PyTuple_SetItem asserts refcnt==1
- resource.c: Different strategy regarding whether to declare
getrusage() and getpagesize() -- #ifdef doesn't work, Linux has
conflicting decls in its headers. Choice: only declare the return
type, not the argument prototype, and not on Linux.
- importdl.c, configure*: set sharedlib extensions properly for NeXT
- configure*, Makefile.in, Modules/Makefile.pre.in: AIX shared libraries
fixed; moved addition of PURIFY to LINKCC to configure
- reopmodule.c, regexmodule.c, regexpr.c, zlibmodule.c: needed casts
added to shup up various compilers.
- _tkinter.c: removed buggy mac #ifndef
- Doc: various Mac documentation changes, added docs for 'ic' module
- PC/make_nt.in: deleted
- test_time.py, test_strftime.py: tweaks to catch %Z (which may return
"")
- test_rotor.py: print b -> print `b`
- Tkinter.py: (tagOrId) -> (tagOrId,)
- Tkinter.py: the Tk class now also has a configure() method and
friends (they have been moved to the Misc class to accomplish this).
- dict.get(key[, default]) returns dict[key] if it exists, or default
if it doesn't. The default defaults to None. This is quicker for
some applications than using either has_key() or try:...except
KeyError:....
- Tools/webchecker/: some small changes to webchecker.py; added
websucker.py (a simple web site mirroring script).
- Dictionary objects now have a get() method (also in UserDict.py).
dict.get(key, default) returns dict[key] if it exists and default
otherwise; default defaults to None.
- Tools/scripts/logmerge.py: print the author, too.
- Changes to import: support for "import a.b.c" is now built in. See
http://grail.cnri.reston.va.us/python/essays/packages.html
for more info. Most important deviations from "ni.py": __init__.py is
executed in the package's namespace instead of as a submodule; and
there's no support for "__" or "__domain__". Note that "ni.py" is not
changed to match this -- it is simply declared obsolete (while at the
same time, it is documented...:-( ).
Unfortunately, "ihooks.py" has not been upgraded (but see "knee.py"
for an example implementation of hierarchical module import written in
Python).
- More changes to import: the site.py module is now imported by
default when Python is initialized; use -S to disable it. The site.py
module extends the path with several more directories: site-packages
inside the lib/python1.5/ directory, site-python in the lib/
directory, and pathnames mentioned in *.pth files found in either of
those directories. See
http://grail.cnri.reston.va.us/python/essays/packages.html
for more info.
- Changes to standard library subdirectory names: those subdirectories
that are not packages have been renamed with a hypen in their name,
e.g. lib-tk, lib-stdwin, plat-win, plat-linux2, plat-sunos5, dos-8x3.
The test suite is now a package -- to run a test, you must now use
"import test.test_foo".
- A completely new re.py module is provided (thanks to Andrew
Kuchling, Tim Peters and Jeffrey Ollie) which uses Philip Hazel's
"pcre" re compiler and engine. For a while, the "old" re.py (which
was new in 1.5a3!) will be kept around as re1.py. The "old" regex
module and underlying parser and engine are still present -- while
regex is now officially obsolete, it will probably take several major
release cycles before it can be removed.
- The posix module now has a strerror() function which translates an
error code to a string.
- The emacs.py module (which was long obsolete) has been removed.
- The universal makefile Misc/Makefile.pre.in now features an
"install" target. By default, installed shared libraries go into
$exec_prefix/lib/python$VERSION/site-packages/.
- The install-sh script is installed with the other configuration
specific files (in the config/ subdirectory).
- It turns out whatsound.py and sndhdr.py were identical modules.
Since there's also an imghdr.py file, I propose to make sndhdr.py the
official one. For compatibility, whatsound.py imports * from
sndhdr.py.
- Class objects have a new attribute, __module__, giving the name of
the module in which they were declared. This is useful for pickle and
for printing the full name of a class exception.
- Many extension modules no longer issue a fatal error when their
initialization fails; the importing code now checks whether an error
occurred during module initialization, and correctly propagates the
exception to the import statement.
- Most extension modules now raise class-based exceptions (except when
-X is used).
- Subtle changes to PyEval_{Save,Restore}Thread(): always swap the
thread state -- just don't manipulate the lock if it isn't there.
- Fixed a bug in Python/getopt.c that made it do the wrong thing when
an option was a single '-'. Thanks to Andrew Kuchling.
- New module mimetypes.py will guess a MIME type from a filename's
extension.
- Windows: the DLL version is now settable via a resource rather than
being hardcoded. This can be used for "branding" a binary Python
distribution.
- urllib.py is now threadsafe -- it now uses re instead of regex, and
sys.exc_info() instead of sys.exc_{type,value}.
- Many other library modules that used to use
sys.exc_{type,value,traceback} are now more thread-safe by virtue of
using sys.exc_info().
- The functions in popen2 have an optional buffer size parameter.
Also, the command argument can now be either a string (passed to the
shell) or a list of arguments (passed directly to execv).
- Alas, the thread support for _tkinter released with 1.5a3 didn't
work. It's been rewritten. The bad news is that it now requires a
modified version of a file in the standard Tcl distribution, which you
must compile with a -I option pointing to the standard Tcl source
tree. For this reason, the thread support is disabled by default.
- The errno extension module adds two tables: errorcode maps errno
numbers to errno names (e.g. EINTR), and errorstr maps them to
message strings. (The latter is redundant because the new call
posix.strerror() now does the same, but alla...) (Marc-Andre Lemburg)
- The readline extension module now provides some interfaces to
internal readline routines that make it possible to write a completer
in Python. An example completer, rlcompleter.py, is provided.
When completing a simple identifier, it completes keywords,
built-ins and globals in __main__; when completing
NAME.NAME..., it evaluates (!) the expression up to the last
dot and completes its attributes.
It's very cool to do "import string" type "string.", hit the
completion key (twice), and see the list of names defined by
the string module!
Tip: to use the tab key as the completion key, call
readline.parse_and_bind("tab: complete")
- The traceback.py module has a new function tb_lineno() by Marc-Andre
Lemburg which extracts the line number from the linenumber table in
the code object. Apparently the traceback object doesn't contains the
right linenumber when -O is used. Rather than guessing whether -O is
on or off, the module itself uses tb_lineno() unconditionally.
- Fixed Demo/tkinter/matt/canvas-moving-or-creating.py: change bind()
to tag_bind() so it works again.
- The pystone script is now a standard library module. Example use:
"import test.pystone; test.pystone.main()".
- The import of the readline module in interactive mode is now also
attempted when -i is specified. (Yes, I know, giving in to Marc-Andre
Lemburg, who asked for this. :-)
- rfc822.py: Entirely rewritten parseaddr() function by Sjoerd
Mullender, to be closer to the standard. This fixes the getaddr()
method. Unfortunately, getaddrlist() is as broken as ever, since it
splits on commas without regard for RFC 822 quoting conventions.
- pprint.py: correctly emit trailing "," in singleton tuples.
- _tkinter.c: export names for its type objects, TkappType and
TkttType.
- pickle.py: use __module__ when defined; fix a particularly hard to
reproduce bug that confuses the memo when temporary objects are
returned by custom pickling interfaces; and a semantic change: when
unpickling the instance variables of an instance, use
inst.__dict__.update(value) instead of a for loop with setattr() over
the value.keys(). This is more consistent (the pickling doesn't use
getattr() either but pickles inst.__dict__) and avoids problems with
instances that have a __setattr__ hook. But it *is* a semantic change
(because the setattr hook is no longer used). So beware!
- config.h is now installed (at last) in
$exec_prefix/include/python1.5/. For most sites, this means that it
is actually in $prefix/include/python1.5/, with all the other Python
include files, since $prefix and $exec_prefix are the same by
default.
- The imp module now supports parts of the functionality to implement
import of hierarchical module names. It now supports find_module()
and load_module() for all types of modules. Docstrings have been
added for those functions in the built-in imp module that are still
relevant (some old interfaces are obsolete). For a sample
implementation of hierarchical module import in Python, see the new
library module knee.py.
- The % operator on string objects now allows arbitrary nested parens
in a %(...)X style format. (Brad Howes)
- Reverse the order in which Setup and Setup.local are passed to the
makesetup script. This allows variable definitions in Setup.local to
override definitions in Setup. (But you'll still have to edit Setup
if you want to disable modules that are enabled by default, or if such
modules need non-standard options.)
- Added PyImport_ImportModuleEx(name, globals, locals, fromlist); this
is like PyImport_ImporModule(name) but receives the globals and locals
dict and the fromlist arguments as well. (The name is a char*; the
others are PyObject*s).
- The 'p' format in the struct extension module alloded to above is
new in 1.5a4.
- The types.py module now uses try-except in a few places to make it
more likely that it can be imported in restricted mode. Some type
names are undefined in that case, e.g. CodeType (inaccessible),
FileType (not always accessible), and TracebackType and FrameType
(inaccessible).
- In urllib.py: added separate administration of temporary files
created y URLopener.retrieve() so cleanup() can properly remove them.
The old code removed everything in tempcache which was a bad idea if
the user had passed a non-temp file into it. Also, in basejoin(),
interpret relative paths starting in "../". This is necessary if the
server uses symbolic links.
- The Windows build procedure and project files are now based on
Microsoft Visual C++ 5.x. The build now takes place in the PCbuild
directory. It is much more robust, and properly builds separate Debug
and Release versions. (The installer will be added shortly.)
- Added casts and changed some return types in regexpr.c to avoid
compiler warnings or errors on some platforms.
- The AIX build tools for shared libraries now supports VPATH. (Donn
Cave)
- By default, disable the "portable" multimedia modules audioop,
imageop, and rgbimg, since they don't work on 64-bit platforms.
- Fixed a nasty bug in cStringIO.c when code was actually using the
close() method (the destructors would try to free certain fields a
second time).
- For those who think they need it, there's a "user.py" module. This
is *not* imported by default, but can be imported to run user-specific
setup commands, ~/.pythonrc.py.
- Various speedups suggested by Fredrik Lundh, Marc-Andre Lemburg,
Vladimir Marangozov, and others.
- Added os.altsep; this is '/' on DOS/Windows, and None on systems
with a sane filename syntax.
- os.py: Write out the dynamic OS choice, to avoid exec statements.
Adding support for a new OS is now a bit more work, but I bet that
'dos' or 'nt' will cover most situations...
- The obsolete exception AccessError is now really gone.
- Tools/faqwiz/: New installation instructions show how to maintain
multiple FAQs. Removed bootstrap script from end of faqwiz.py module.
Added instructions to bootstrap script, too. Version bumped to 0.8.1.
Added <html>...</html> feature suggested by Skip Montanaro. Added
leading text for Roulette, default to 'Hit Reload ...'. Fix typo in
default SRCDIR.
- Documentation for the relatively new modules "keyword" and "symbol"
has been added (to the end of the section on the parser extension
module).
- In module bisect.py, but functions have two optional argument 'lo'
and 'hi' which allow you to specify a subsequence of the array to
operate on.
- In ftplib.py, changed most methods to return their status (even when
it is always "200 OK") rather than swallowing it.
- main() now calls setlocale(LC_ALL, ""), if setlocale() and
<locale.h> are defined.
- Changes to configure.in, the configure script, and both
Makefile.pre.in files, to support SGI's SGI_ABI platform selection
environment variable.
======================================================================
From 1.4 to 1.5a3
=================
Security
--------
- If you are using the setuid script C wrapper (Misc/setuid-prog.c),
please use the new version. The old version has a huge security leak.
Miscellaneous
-------------
- Because of various (small) incompatible changes in the Python
bytecode interpreter, the magic number for .pyc files has changed
again.
- The default module search path is now much saner. Both on Unix and
Windows, it is essentially derived from the path to the executable
(which can be overridden by setting the environment variable
$PYTHONHOME). The value of $PYTHONPATH on Windows is now inserted in
front of the default path, like in Unix (instead of overriding the
default path). On Windows, the directory containing the executable is
added to the end of the path.
- A new version of python-mode.el for Emacs has been included. Also,
a new file ccpy-style.el has been added to configure Emacs cc-mode for
the preferred style in Python C sources.
- On Unix, when using sys.argv[0] to insert the script directory in
front of sys.path, expand a symbolic link. You can now install a
program in a private directory and have a symbolic link to it in a
public bin directory, and it will put the private directory in the
module search path. Note that the symlink is expanded in sys.path[0]
but not in sys.argv[0], so you can still tell the name by which you
were invoked.
- It is now recommended to use ``#!/usr/bin/env python'' instead of
``#!/usr/local/bin/python'' at the start of executable scripts, except
for CGI scripts. It has been determined that the use of /usr/bin/env
is more portable than that of /usr/local/bin/python -- scripts almost
never have to be edited when the Python interpreter lives in a
non-standard place. Note that this doesn't work for CGI scripts since
the python executable often doesn't live in the HTTP server's default
search path.
- The silly -s command line option and the corresponding
PYTHONSUPPRESS environment variable (and the Py_SuppressPrint global
flag in the Python/C API) are gone.
- Most problems on 64-bit platforms should now be fixed. Andrew
Kuchling helped. Some uncommon extension modules are still not
clean (image and audio ops?).
- Fixed a bug where multiple anonymous tuple arguments would be mixed up
when using the debugger or profiler (reported by Just van Rossum).
The simplest example is ``def f((a,b),(c,d)): print a,b,c,d''; this
would print the wrong value when run under the debugger or profiler.
- The hacks that the dictionary implementation used to speed up
repeated lookups of the same C string were removed; these were a
source of subtle problems and don't seem to serve much of a purpose
any longer.
- All traces of support for the long dead access statement have been
removed from the sources.
- Plugged the two-byte memory leak in the tokenizer when reading an
interactive EOF.
- There's a -O option to the interpreter that removes SET_LINENO
instructions and assert statements (see below); it uses and produces
.pyo files instead of .pyc files. The speedup is only a few percent
in most cases. The line numbers are still available in the .pyo file,
as a separate table (which is also available in .pyc files). However,
the removal of the SET_LINENO instructions means that the debugger
(pdb) can't set breakpoints on lines in -O mode. The traceback module
contains a function to extract a line number from the code object
referenced in a traceback object. In the future it should be possible
to write external bytecode optimizers that create better optimized
.pyo files, and there should be more control over optimization;
consider the -O option a "teaser". Without -O, the assert statement
actually generates code that first checks __debug__; if this variable
is false, the assertion is not checked. __debug__ is a built-in
variable whose value is initialized to track the -O flag (it's true
iff -O is not specified). With -O, no code is generated for assert
statements, nor for code of the form ``if __debug__: <something>''.
Sorry, no further constant folding happens.
Performance
-----------
- It's much faster (almost twice for pystone.py -- see
Tools/scripts). See the entry on string interning below.
- Some speedup by using separate free lists for method objects (both
the C and the Python variety) and for floating point numbers.
- Big speedup by allocating frame objects with a single malloc() call.
The Python/C API for frames is changed (you shouldn't be using this
anyway).
- Significant speedup by inlining some common opcodes for common operand
types (e.g. i+i, i-i, and list[i]). Fredrik Lundh.
- Small speedup by reordering the method tables of some common
objects (e.g. list.append is now first).
- Big optimization to the read() method of file objects. A read()
without arguments now attempts to use fstat to allocate a buffer of
the right size; for pipes and sockets, it will fall back to doubling
the buffer size. While that the improvement is real on all systems,
it is most dramatic on Windows.
Documentation
-------------
- Many new pieces of library documentation were contributed, mostly by
Andrew Kuchling. Even cmath is now documented! There's also a
chapter of the library manual, "libundoc.tex", which provides a
listing of all undocumented modules, plus their status (e.g. internal,
obsolete, or in need of documentation). Also contributions by Sue
Williams, Skip Montanaro, and some module authors who succumbed to
pressure to document their own contributed modules :-). Note that
printing the documentation now kills fewer trees -- the margins have
been reduced.
- I have started documenting the Python/C API. Unfortunately this project
hasn't been completed yet. It will be complete before the final release of
Python 1.5, though. At the moment, it's better to read the LaTeX source
than to attempt to run it through LaTeX and print the resulting dvi file.
- The posix module (and hence os.py) now has doc strings! Thanks to Neil
Schemenauer. I received a few other contributions of doc strings. In most
other places, doc strings are still wishful thinking...
Language changes
----------------
- Private variables with leading double underscore are now a permanent
feature of the language. (These were experimental in release 1.4. I have
favorable experience using them; I can't label them "experimental"
forever.)
- There's new string literal syntax for "raw strings". Prefixing a string
literal with the letter r (or R) disables all escape processing in the
string; for example, r'\n' is a two-character string consisting of a
backslash followed by the letter n. This combines with all forms of string
quotes; it is actually useful for triple quoted doc strings which might
contain references to \n or \t. An embedded quote prefixed with a
backslash does not terminate the string, but the backslash is still
included in the string; for example, r'\'' is a two-character string
consisting of a backslash and a quote. (Raw strings are also
affectionately known as Robin strings, after their inventor, Robin
Friedrich.)
- There's a simple assert statement, and a new exception
AssertionError. For example, ``assert foo > 0'' is equivalent to ``if
not foo > 0: raise AssertionError''. Sorry, the text of the asserted
condition is not available; it would be too complicated to generate
code for this (since the code is generated from a parse tree).
However, the text is displayed as part of the traceback!
- The raise statement has a new feature: when using "raise SomeClass,
somevalue" where somevalue is not an instance of SomeClass, it
instantiates SomeClass(somevalue). In 1.5a4, if somevalue is an
instance of a *derived* class of SomeClass, the exception class raised
is set to somevalue.__class__, and SomeClass is ignored after that.
- Duplicate keyword arguments are now detected at compile time;
f(a=1,a=2) is now a syntax error.
Changes to builtin features
---------------------------
- There's a new exception FloatingPointError (used only by Lee Busby's
patches to catch floating point exceptions, at the moment).
- The obsolete exception ConflictError (presumably used by the long
obsolete access statement) has been deleted.
- There's a new function sys.exc_info() which returns the tuple
(sys.exc_type, sys.exc_value, sys.exc_traceback) in a thread-safe way.
- There's a new variable sys.executable, pointing to the executable file
for the Python interpreter.
- The sort() methods for lists no longer uses the C library qsort(); I
wrote my own quicksort implementation, with lots of help (in the form
of a kind of competition) from Tim Peters. This solves a bug in
dictionary comparisons on some Solaris versions when Python is built
with threads, and makes sorting lists even faster.
- The semantics of comparing two dictionaries have changed, to make
comparison of unequal dictionaries faster. A shorter dictionary is
always considered smaller than a larger dictionary. For dictionaries
of the same size, the smallest differing element determines the
outcome (which yields the same results as before in this case, without
explicit sorting). Thanks to Aaron Watters for suggesting something
like this.
- The semantics of try-except have changed subtly so that calling a
function in an exception handler that itself raises and catches an
exception no longer overwrites the sys.exc_* variables. This also
alleviates the problem that objects referenced in a stack frame that
caught an exception are kept alive until another exception is caught
-- the sys.exc_* variables are restored to their previous value when
returning from a function that caught an exception.
- There's a new "buffer" interface. Certain objects (e.g. strings and
arrays) now support the "buffer" protocol. Buffer objects are acceptable
whenever formerly a string was required for a write operation; mutable
buffer objects can be the target of a read operation using the call
f.readinto(buffer). A cool feature is that regular expression matching now
also work on array objects. Contribution by Jack Jansen. (Needs
documentation.)
- String interning: dictionary lookups are faster when the lookup
string object is the same object as the key in the dictionary, not
just a string with the same value. This is done by having a pool of
"interned" strings. Most names generated by the interpreter are now
automatically interned, and there's a new built-in function intern(s)
that returns the interned version of a string. Interned strings are
not a different object type, and interning is totally optional, but by
interning most keys a speedup of about 15% was obtained for the
pystone benchmark.
- Dictionary objects have several new methods; clear() and copy() have
the obvious semantics, while update(d) merges the contents of another
dictionary d into this one, overriding existing keys. The dictionary
implementation file is now called dictobject.c rather than the
confusing mappingobject.c.
- The intrinsic function dir() is much smarter; it looks in __dict__,
__members__ and __methods__.
- The intrinsic functions int(), long() and float() can now take a
string argument and then do the same thing as string.atoi(),
string.atol(), and string.atof(). No second 'base' argument is
allowed, and complex() does not take a string (nobody cared enough).
- When a module is deleted, its globals are now deleted in two phases.
In the first phase, all variables whose name begins with exactly one
underscore are replaced by None; in the second phase, all variables
are deleted. This makes it possible to have global objects whose
destructors depend on other globals. The deletion order within each
phase is still random.
- It is no longer an error for a function to be called without a
global variable __builtins__ -- an empty directory will be provided
by default.
- Guido's corollary to the "Don Beaudry hook": it is now possible to
do metaprogramming by using an instance as a base class. Not for the
faint of heart; and undocumented as yet, but basically if a base class
is an instance, its class will be instantiated to create the new
class. Jim Fulton will love it -- it also works with instances of his
"extension classes", since it is triggered by the presence of a
__class__ attribute on the purported base class. See
Demo/metaclasses/index.html for an explanation and see that directory
for examples.
- Another change is that the Don Beaudry hook is now invoked when
*any* base class is special. (Up to 1.5a3, the *last* special base
class is used; in 1.5a4, the more rational choice of the *first*
special base class is used.)
- New optional parameter to the readlines() method of file objects.
This indicates the number of bytes to read (the actual number of bytes
read will be somewhat larger due to buffering reading until the end of
the line). Some optimizations have also been made to speed it up (but
not as much as read()).
- Complex numbers no longer have the ".conj" pseudo attribute; use
z.conjugate() instead, or complex(z.real, -z.imag). Complex numbers
now *do* support the __members__ and __methods__ special attributes.
- The complex() function now looks for a __complex__() method on class
instances before giving up.
- Long integers now support arbitrary shift counts, so you can now
write 1L<<1000000, memory permitting. (Python 1.4 reports "outrageous
shift count for this.)
- The hex() and oct() functions have been changed so that for regular
integers, they never emit a minus sign. For example, on a 32-bit
machine, oct(-1) now returns '037777777777' and hex(-1) returns
'0xffffffff'. While this may seem inconsistent, it is much more
useful. (For long integers, a minus sign is used as before, to fit
the result in memory :-)
- The hash() function computes better hashes for several data types,
including strings, floating point numbers, and complex numbers.
New extension modules
---------------------
- New extension modules cStringIO.c and cPickle.c, written by Jim
Fulton and other folks at Digital Creations. These are much more
efficient than their Python counterparts StringIO.py and pickle.py,
but don't support subclassing. cPickle.c clocks up to 1000 times
faster than pickle.py; cStringIO.c's improvement is less dramatic but
still significant.
- New extension module zlibmodule.c, interfacing to the free zlib
library (gzip compatible compression). There's also a module gzip.py
which provides a higher level interface. Written by Andrew Kuchling
and Jeremy Hylton.
- New module readline; see the "miscellaneous" section above.
- New Unix extension module resource.c, by Jeremy Hylton, provides
access to getrlimit(), getrusage(), setrusage(), getpagesize(), and
related symbolic constants.
- New extension puremodule.c, by Barry Warsaw, which interfaces to the
Purify(TM) C API. See also the file Misc/PURIFY.README. It is also
possible to enable Purify by simply setting the PURIFY Makefile
variable in the Modules/Setup file.
Changes in extension modules
----------------------------
- The struct extension module has several new features to control byte
order and word size. It supports reading and writing IEEE floats even
on platforms where this is not the native format. It uses uppercase
format codes for unsigned integers of various sizes (always using
Python long ints for 'I' and 'L'), 's' with a size prefix for strings,
and 'p' for "Pascal strings" (with a leading length byte, included in
the size; blame Hannu Krosing; new in 1.5a4). A prefix '>' forces
big-endian data and '<' forces little-endian data; these also select
standard data sizes and disable automatic alignment (use pad bytes as
needed).
- The array module supports uppercase format codes for unsigned data
formats (like the struct module).
- The fcntl extension module now exports the needed symbolic
constants. (Formerly these were in FCNTL.py which was not available
or correct for all platforms.)
- The extension modules dbm, gdbm and bsddb now check that the
database is still open before making any new calls.
- The dbhash module is no more. Use bsddb instead. (There's a third
party interface for the BSD 2.x code somewhere on the web; support for
bsddb will be deprecated.)
- The gdbm module now supports a sync() method.
- The socket module now has some new functions: getprotobyname(), and
the set {ntoh,hton}{s,l}().
- Various modules now export their type object: socket.SocketType,
array.ArrayType.
- The socket module's accept() method now returns unknown addresses as
a tuple rather than raising an exception. (This can happen in
promiscuous mode.) Theres' also a new function getprotobyname().
- The pthread support for the thread module now works on most platforms.
- STDWIN is now officially obsolete. Support for it will eventually
be removed from the distribution.
- The binascii extension module is now hopefully fully debugged.
(XXX Oops -- Fredrik Lundh promised me a uuencode fix that I never
received.)
- audioop.c: added a ratecv() function; better handling of overflow in
add().
- posixmodule.c: now exports the O_* flags (O_APPEND etc.). On
Windows, also O_TEXT and O_BINARY. The 'error' variable (the
exception is raises) is renamed -- its string value is now "os.error",
so newbies don't believe they have to import posix (or nt) to catch
it when they see os.error reported as posix.error. The execve()
function now accepts any mapping object for the environment.
- A new version of the al (audio library) module for SGI was
contributed by Sjoerd Mullender.
- The regex module has a new function get_syntax() which retrieves the
syntax setting set by set_syntax(). The code was also sanitized,
removing worries about unclean error handling. See also below for its
successor, re.py.
- The "new" module (which creates new objects of various types) once
again has a fully functioning new.function() method. Dangerous as
ever! Also, new.code() has several new arguments.
- A problem has been fixed in the rotor module: on systems with signed
characters, rotor-encoded data was not portable when the key contained
8-bit characters. Also, setkey() now requires its argument rather
than having broken code to default it.
- The sys.builtin_module_names variable is now a tuple. Another new
variables in sys is sys.executable (the full path to the Python
binary, if known).
- The specs for time.strftime() have undergone some revisions. It
appears that not all format characters are supported in the same way
on all platforms. Rather than reimplement it, we note these
differences in the documentation, and emphasize the shared set of
features. There's also a thorough test set (that occasionally finds
problems in the C library implementation, e.g. on some Linuxes),
thanks to Skip Montanaro.
- The nis module seems broken when used with NIS+; unfortunately
nobody knows how to fix it. It should still work with old NIS.
New library modules
-------------------
- New (still experimental) Perl-style regular expression module,
re.py, which uses a new interface for matching as well as a new
syntax; the new interface avoids the thread-unsafety of the regex
interface. This comes with a helper extension reopmodule.c and vastly
rewritten regexpr.c. Most work on this was done by Jeffrey Ollie, Tim
Peters, and Andrew Kuchling. See the documentation libre.tex. In
1.5, the old regex module is still fully supported; in the future, it
will become obsolete.
- New module gzip.py; see zlib above.
- New module keyword.py exports knowledge about Python's built-in
keywords. (New version by Ka-Ping Yee.)
- New module pprint.py (with documentation) which supports
pretty-printing of lists, tuples, & dictionaries recursively. By Fred
Drake.
- New module code.py. The function code.compile_command() can
determine whether an interactively entered command is complete or not,
distinguishing incomplete from invalid input. (XXX Unfortunately,
this seems broken at this moment, and I don't have the time to fix
it. It's probably better to add an explicit interface to the parser
for this.)
- There is now a library module xdrlib.py which can read and write the
XDR data format as used by Sun RPC, for example. It uses the struct
module.
Changes in library modules
--------------------------
- Module codehack.py is now completely obsolete.
- The pickle.py module has been updated to make it compatible with the
new binary format that cPickle.c produces. By default it produces the
old all-ASCII format compatible with the old pickle.py, still much
faster than pickle.py; it will read both formats automatically. A few
other updates have been made.
- A new helper module, copy_reg.py, is provided to register extensions
to the pickling code.
- Revamped module tokenize.py is much more accurate and has an
interface that makes it a breeze to write code to colorize Python
source code. Contributed by Ka-Ping Yee.
- In ihooks.py, ModuleLoader.load_module() now closes the file under
all circumstances.
- The tempfile.py module has a new class, TemporaryFile, which creates
an open temporary file that will be deleted automatically when
closed. This works on Windows and MacOS as well as on Unix. (Jim
Fulton.)
- Changes to the cgi.py module: Most imports are now done at the
top of the module, which provides a speedup when using ni (Jim
Fulton). The problem with file upload to a Windows platform is solved
by using the new tempfile.TemporaryFile class; temporary files are now
always opened in binary mode (Jim Fulton). The cgi.escape() function
now takes an optional flag argument that quotes '"' to '"'. It
is now possible to invoke cgi.py from a command line script, to test
cgi scripts more easily outside an http server. There's an optional
limit to the size of uploads to POST (Skip Montanaro). Added a
'strict_parsing' option to all parsing functions (Jim Fulton). The
function parse_qs() now uses urllib.unquote() on the name as well as
the value of fields (Clarence Gardner). The FieldStorage class now
has a __len__() method.
- httplib.py: the socket object is no longer closed; all HTTP/1.*
responses are now accepted; and it is now thread-safe (by not using
the regex module).
- BaseHTTPModule.py: treat all HTTP/1.* versions the same.
- The popen2.py module is now rewritten using a class, which makes
access to the standard error stream and the process id of the
subprocess possible.
- Added timezone support to the rfc822.py module, in the form of a
getdate_tz() method and a parsedate_tz() function; also a mktime_tz().
Also added recognition of some non-standard date formats, by Lars
Wirzenius, and RFC 850 dates (Chris Lawrence).
- mhlib.py: various enhancements, including almost compatible parsing
of message sequence specifiers without invoking a subprocess. Also
added a createmessage() method by Lars Wirzenius.
- The StringIO.StringIO class now supports readline(nbytes). (Lars
Wirzenius.) (Of course, you should be using cStringIO for performance.)
- UserDict.py supports the new dictionary methods as well.
- Improvements for whrandom.py by Tim Peters: use 32-bit arithmetic to
speed it up, and replace 0 seed values by 1 to avoid degeneration.
A bug was fixed in the test for invalid arguments.
- Module ftplib.py: added support for parsing a .netrc file (Fred
Drake). Also added an ntransfercmd() method to the FTP class, which
allows access to the expected size of a transfer when available, and a
parse150() function to the module which parses the corresponding 150
response.
- urllib.py: the ftp cache is now limited to 10 entries. Added
quote_plus() and unquote_plus() functions which are like quote() and
unquote() but also replace spaces with '+' or vice versa, for
encoding/decoding CGI form arguments. Catch all errors from the ftp
module. HTTP requests now add the Host: header line. The proxy
variable names are now mapped to lower case, for Windows. The
spliturl() function no longer erroneously throws away all data past
the first newline. The basejoin() function now intereprets "../"
correctly. I *believe* that the problems with "exception raised in
__del__" under certain circumstances have been fixed (mostly by
changes elsewher in the interpreter).
- In urlparse.py, there is a cache for results in urlparse.urlparse();
its size limit is set to 20. Also, new URL schemes shttp, https, and
snews are "supported".
- shelve.py: use cPickle and cStringIO when available. Also added
a sync() method, which calls the database's sync() method if there is
one.
- The mimetools.py module now uses the available Python modules for
decoding quoted-printable, uuencode and base64 formats, rather than
creating a subprocess.
- The python debugger (pdb.py, and its base class bdb.py) now support
conditional breakpoints. See the docs.
- The modules base64.py, uu.py and quopri.py can now be used as simple
command line utilities.
- Various small fixes to the nntplib.py module that I can't bother to
document in detail.
- Sjoerd Mullender's mimify.py module now supports base64 encoding and
includes functions to handle the funny encoding you sometimes see in mail
headers. It is now documented.
- mailbox.py: Added BabylMailbox. Improved the way the mailbox is
gotten from the environment.
- Many more modules now correctly open files in binary mode when this
is necessary on non-Unix platforms.
- The copying functions in the undocumented module shutil.py are
smarter.
- The Writer classes in the formatter.py module now have a flush()
method.
- The sgmllib.py module accepts hyphens and periods in the middle of
attribute names. While this is against the SGML standard, there is
some HTML out there that uses this...
- The interface for the Python bytecode disassembler module, dis.py,
has been enhanced quite a bit. There's now one main function,
dis.dis(), which takes almost any kind of object (function, module,
class, instance, method, code object) and disassembles it; without
arguments it disassembles the last frame of the last traceback. The
other functions have changed slightly, too.
- The imghdr.py module recognizes new image types: BMP, PNG.
- The string.py module has a new function replace(str, old, new,
[maxsplit]) which does substring replacements. It is actually
implemented in C in the strop module. The functions [r]find() an
[r]index() have an optional 4th argument indicating the end of the
substring to search, alsoo implemented by their strop counterparts.
(Remember, never import strop -- import string uses strop when
available with zero overhead.)
- The string.join() function now accepts any sequence argument, not
just lists and tuples.
- The string.maketrans() requires its first two arguments to be
present. The old version didn't require them, but there's not much
point without them, and the documentation suggests that they are
required, so we fixed the code to match the documentation.
- The regsub.py module has a function clear_cache(), which clears its
internal cache of compiled regular expressions. Also, the cache now
takes the current syntax setting into account. (However, this module
is now obsolete -- use the sub() or subn() functions or methods in the
re module.)
- The undocumented module Complex.py has been removed, now that Python
has built-in complex numbers. A similar module remains as
Demo/classes/Complex.py, as an example.
Changes to the build process
----------------------------
- The way GNU readline is configured is totally different. The
--with-readline configure option is gone. It is now an extension
module, which may be loaded dynamically. You must enable it (and
specify the correct linraries to link with) in the Modules/Setup file.
Importing the module installs some hooks which enable command line
editing. When the interpreter shell is invoked interactively, it
attempts to import the readline module; when this fails, the default
input mechanism is used. The hook variables are PyOS_InputHook and
PyOS_ReadlineFunctionPointer. (Code contributed by Lee Busby, with
ideas from William Magro.)
- New build procedure: a single library, libpython1.5.a, is now built,
which contains absolutely everything except for a one-line main()
program (which calls Py_Main(argc, argv) to start the interpreter
shell). This makes life much simpler for applications that need to
embed Python. The serial number of the build is now included in the
version string (sys.version).
- As far as I can tell, neither gcc -Wall nor the Microsoft compiler
emits a single warning any more when compiling Python.
- A number of new Makefile variables have been added for special
situations, e.g. LDLAST is appended to the link command. These are
used by editing the Makefile or passing them on the make command
line.
- A set of patches from Lee Busby has been integrated that make it
possible to catch floating point exceptions. Use the configure option
--with-fpectl to enable the patches; the extension modules fpectl and
fpetest provide control to enable/disable and test the feature,
respectively.
- The support for shared libraries under AIX is now simpler and more
robust. Thanks to Vladimir Marangozov for revamping his own patches!
- The Modules/makesetup script now reads a file Setup.local as well as
a file Setup. Most changes to the Setup script can be done by editing
Setup.local instead, which makes it easier to carry a particular setup
over from one release to the next.
- The Modules/makesetup script now copies any "include" lines it
encounters verbatim into the output Makefile. It also recognizes .cxx
and .cpp as C++ source files.
- The configure script is smarter about C compiler options; e.g. with
gcc it uses -O2 and -g when possible, and on some other platforms it
uses -Olimit 1500 to avoid a warning from the optimizer about the main
loop in ceval.c (which has more than 1000 basic blocks).
- The configure script now detects whether malloc(0) returns a NULL
pointer or a valid block (of length zero). This avoids the nonsense
of always adding one byte to all malloc() arguments on most platforms.
- The configure script has a new option, --with-dec-threads, to enable
DEC threads on DEC Alpha platforms. Also, --with-threads is now an
alias for --with-thread (this was the Most Common Typo in configure
arguments).
- Many changes in Doc/Makefile; amongst others, latex2html is now used
to generate HTML from all latex documents.
Change to the Python/C API
--------------------------
- Because some interfaces have changed, the PYTHON_API macro has been
bumped. Most extensions built for the old API version will still run,
but I can't guarantee this. Python prints a warning message on
version mismatches; it dumps core when the version mismatch causes a
serious problem :-)
- I've completed the Grand Renaming, with the help of Roger Masse and
Barry Warsaw. This makes reading or debugging the code much easier.
Many other unrelated code reorganizations have also been carried out.
The allobjects.h header file is gone; instead, you would have to
include Python.h followed by rename2.h. But you're better off running
Tools/scripts/fixcid.py -s Misc/RENAME on your source, so you can omit
the rename2.h; it will disappear in the next release.
- Various and sundry small bugs in the "abstract" interfaces have been
fixed. Thanks to all the (involuntary) testers of the Python 1.4
version! Some new functions have been added, e.g. PySequence_List(o),
equivalent to list(o) in Python.
- New API functions PyLong_FromUnsignedLong() and
PyLong_AsUnsignedLong().
- The API functions in the file cgensupport.c are no longer
supported. This file has been moved to Modules and is only ever
compiled when the SGI specific 'gl' module is built.
- PyObject_Compare() can now raise an exception. Check with
PyErr_Occurred(). The comparison function in an object type may also
raise an exception.
- The slice interface uses an upper bound of INT_MAX when no explicit
upper bound is given (e.x. for a[1:]). It used to ask the object for
its length and do the calculations.
- Support for multiple independent interpreters. See Doc/api.tex,
functions Py_NewInterpreter() and Py_EndInterpreter(). Since the
documentation is incomplete, also see the new Demo/pysvr example
(which shows how to use these in a threaded application) and the
source code.
- There is now a Py_Finalize() function which "de-initializes"
Python. It is possible to completely restart the interpreter
repeatedly by calling Py_Finalize() followed by Py_Initialize(). A
change of functionality in Py_Initialize() means that it is now a
fatal error to call it while the interpreter is already initialized.
The old, half-hearted Py_Cleanup() routine is gone. Use of Py_Exit()
is deprecated (it is nothing more than Py_Finalize() followed by
exit()).
- There are no known memory leaks left. While Py_Finalize() doesn't
free *all* allocated memory (some of it is hard to track down),
repeated calls to Py_Finalize() and Py_Initialize() do not create
unaccessible heap blocks.
- There is now explicit per-thread state. (Inspired by, but not the
same as, Greg Stein's free threading patches.)
- There is now better support for threading C applications. There are
now explicit APIs to manipulate the interpreter lock. Read the source
or the Demo/pysvr example; the new functions are
PyEval_{Acquire,Release}{Lock,Thread}().
- The test macro DEBUG has changed to Py_DEBUG, to avoid interference
with other libraries' DEBUG macros. Likewise for any other test
macros that didn't yet start with Py_.
- New wrappers around malloc() and friends: Py_Malloc() etc. call
malloc() and call PyErr_NoMemory() when it fails; PyMem_Malloc() call
just malloc(). Use of these wrappers could be essential if multiple
memory allocators exist (e.g. when using certain DLL setups under
Windows). (Idea by Jim Fulton.)
- New C API PyImport_Import() which uses whatever __import__() hook
that is installed for the current execution environment. By Jim
Fulton.
- It is now possible for an extension module's init function to fail
non-fatally, by calling one of the PyErr_* functions and returning.
- The PyInt_AS_LONG() and PyFloat_AS_DOUBLE() macros now cast their
argument to the proper type, like the similar PyString macros already
did. (Suggestion by Marc-Andre Lemburg.) Similar for PyList_GET_SIZE
and PyList_GET_ITEM.
- Some of the Py_Get* function, like Py_GetVersion() (but not yet
Py_GetPath()) are now declared as returning a const char *. (More
should follow.)
- Changed the run-time library to check for exceptions after object
comparisons. PyObject_Compare() can now return an exception; use
PyErr_Occurred() to check (there is *no* special return value).
- PyFile_WriteString() and Py_Flushline() now return error indicators
instead of clearing exceptions. This fixes an obscure bug where using
these would clear a pending exception, discovered by Just van Rossum.
- There's a new function, PyArg_ParseTupleAndKeywords(), which parses
an argument list including keyword arguments. Contributed by Geoff
Philbrick.
- PyArg_GetInt() is gone.
- It's no longer necessary to include graminit.h when calling one of
the extended parser API functions. The three public grammar start
symbols are now in Python.h as Py_single_input, Py_file_input, and
Py_eval_input.
- The CObject interface has a new function,
PyCObject_Import(module, name). It calls PyCObject_AsVoidPtr()
on the object referenced by "module.name".
Tkinter
-------
- On popular demand, _tkinter once again installs a hook for readline
that processes certain Tk events while waiting for the user to type
(using PyOS_InputHook).
- A patch by Craig McPheeters plugs the most obnoxious memory leaks,
caused by command definitions referencing widget objects beyond their
lifetime.
- New standard dialog modules: tkColorChooser.py, tkCommonDialog.py,
tkMessageBox.py, tkFileDialog.py, tkSimpleDialog.py These interface
with the new Tk dialog scripts, and provide more "native platform"
style file selection dialog boxes on some platforms. Contributed by
Fredrik Lundh.
- Tkinter.py: when the first Tk object is destroyed, it sets the
hiddel global _default_root to None, so that when another Tk object is
created it becomes the new default root. Other miscellaneous
changes and fixes.
- The Image class now has a configure method.
- Added a bunch of new winfo options to Tkinter.py; we should now be
up to date with Tk 4.2. The new winfo options supported are:
mananger, pointerx, pointerxy, pointery, server, viewable, visualid,
visualsavailable.
- The broken bind() method on Canvas objects defined in the Canvas.py
module has been fixed. The CanvasItem and Group classes now also have
an unbind() method.
- The problem with Tkinter.py falling back to trying to import
"tkinter" when "_tkinter" is not found has been fixed -- it no longer
tries "tkinter", ever. This makes diagnosing the problem "_tkinter
not configured" much easier and will hopefully reduce the newsgroup
traffic on this topic.
- The ScrolledText module once again supports the 'cnf' parameter, to
be compatible with the examples in Mark Lutz' book (I know, I know,
too late...)
- The _tkinter.c extension module has been revamped. It now support
Tk versions 4.1 through 8.0; support for 4.0 has been dropped. It
works well under Windows and Mac (with the latest Tk ports to those
platforms). It also supports threading -- it is safe for one
(Python-created) thread to be blocked in _tkinter.mainloop() while
other threads modify widgets. To make the changes visible, those
threads must use update_idletasks()method. (The patch for threading
in 1.5a3 was broken; in 1.5a4, it is back in a different version,
which requires access to the Tcl sources to get it to work -- hence it
is disabled by default.)
- A bug in _tkinter.c has been fixed, where Split() with a string
containing an unmatched '"' could cause an exception or core dump.
- Unfortunately, on Windows and Mac, Tk 8.0 no longer supports
CreateFileHandler, so _tkinter.createfilehandler is not available on
those platforms when using Tk 8.0 or later. I will have to rethink
how to interface with Tcl's lower-level event mechanism, or with its
channels (which are like Python's file-like objects). Jack Jansen has
provided a fix for the Mac, so createfilehandler *is* actually
supported there; maybe I can adapt his fix for Windows.
Tools and Demos
---------------
- A new regression test suite is provided, which tests most of the
standard and built-in modules. The regression test is run by invoking
the script Lib/test/regrtest.py. Barry Warsaw wrote the test harnass;
he and Roger Masse contributed most of the new tests.
- New tool: faqwiz -- the CGI script that is used to maintain the
Python FAQ (http://grail.cnri.reston.va.us/cgi-bin/faqw.py). In
Tools/faqwiz.
- New tool: webchecker -- a simple extensible web robot that, when
aimed at a web server, checks that server for dead links. Available
are a command line utility as well as a Tkinter based GUI version. In
Tools/webchecker. A simplified version of this program is dissected
in my article in O'Reilly's WWW Journal, the issue on Scripting
Languages (Vol 2, No 2); Scripting the Web with Python (pp 97-120).
Includes a parser for robots.txt files by Skip Montanaro.
- New small tools: cvsfiles.py (prints a list of all files under CVS
n a particular directory tree), treesync.py (a rather Guido-specific
script to synchronize two source trees, one on Windows NT, the other
one on Unix under CVS but accessible from the NT box), and logmerge.py
(sort a collection of RCS or CVS logs by date). In Tools/scripts.
- The freeze script now also works under Windows (NT). Another
feature allows the -p option to be pointed at the Python source tree
instead of the installation prefix. This was loosely based on part of
xfreeze by Sam Rushing and Bill Tutt.
- New examples (Demo/extend) that show how to use the generic
extension makefile (Misc/Makefile.pre.in).
- Tools/scripts/h2py.py now supports C++ comments.
- Tools/scripts/pystone.py script is upgraded to version 1.1; there
was a bug in version 1.0 (distributed with Python 1.4) that leaked
memory. Also, in 1.1, the LOOPS variable is incremented to 10000.
- Demo/classes/Rat.py completely rewritten by Sjoerd Mullender.
Windows (NT and 95)
-------------------
- New project files for Developer Studio (Visual C++) 5.0 for Windows
NT (the old VC++ 4.2 Makefile is also still supported, but will
eventually be withdrawn due to its bulkiness).
- See the note on the new module search path in the "Miscellaneous" section
above.
- Support for Win32s (the 32-bit Windows API under Windows 3.1) is
basically withdrawn. If it still works for you, you're lucky.
- There's a new extension module, msvcrt.c, which provides various
low-level operations defined in the Microsoft Visual C++ Runtime Library.
These include locking(), setmode(), get_osfhandle(), set_osfhandle(), and
console I/O functions like kbhit(), getch() and putch().
- The -u option not only sets the standard I/O streams to unbuffered
status, but also sets them in binary mode. (This can also be done
using msvcrt.setmode(), by the way.)
- The, sys.prefix and sys.exec_prefix variables point to the directory
where Python is installed, or to the top of the source tree, if it was run
from there.
- The various os.path modules (posixpath, ntpath, macpath) now support
passing more than two arguments to the join() function, so
os.path.join(a, b, c) is the same as os.path.join(a, os.path.join(b,
c)).
- The ntpath module (normally used as os.path) supports ~ to $HOME
expansion in expanduser().
- The freeze tool now works on Windows.
- See also the Tkinter category for a sad note on
_tkinter.createfilehandler().
- The truncate() method for file objects now works on Windows.
- Py_Initialize() is no longer called when the DLL is loaded. You
must call it yourself.
- The time module's clock() function now has good precision through
the use of the Win32 API QueryPerformanceCounter().
- Mark Hammond will release Python 1.5 versions of PythonWin and his
other Windows specific code: the win32api extensions, COM/ActiveX
support, and the MFC interface.
Mac
---
- As always, the Macintosh port will be done by Jack Jansen. He will
make a separate announcement for the Mac specific source code and the
binary distribution(s) when these are ready.
======================================================================
=====================================
==> Release 1.4 (October 25 1996) <==
=====================================
(Starting in reverse chronological order:)
- Changed disclaimer notice.
- Added SHELL=/bin/sh to Misc/Makefile.pre.in -- some Make versions
default to the user's login shell.
- In Lib/tkinter/Tkinter.py, removed bogus binding of <Delete> in Text
widget, and bogus bspace() function.
- In Lib/cgi.py, bumped __version__ to 2.0 and restored a truncated
paragraph.
- Fixed the NT Makefile (PC/vc40.mak) for VC 4.0 to set /MD for all
subprojects, and to remove the (broken) experimental NumPy
subprojects.
- In Lib/py_compile.py, cast mtime to long() so it will work on Mac
(where os.stat() returns mtimes as floats.)
- Set self.rfile unbuffered (like self.wfile) in SocketServer.py, to
fix POST in CGIHTTPServer.py.
- Version 2.83 of Misc/python-mode.el for Emacs is included.
- In Modules/regexmodule.c, fixed symcomp() to correctly handle a new
group starting immediately after a group tag.
- In Lib/SocketServer.py, changed the mode for rfile to unbuffered.
- In Objects/stringobject.c, fixed the compare function to do the
first char comparison in unsigned mode, for consistency with the way
other characters are compared by memcmp().
- In Lib/tkinter/Tkinter.py, fixed Scale.get() to support floats.
- In Lib/urllib.py, fix another case where openedurl wasn't set.
(XXX Sorry, the rest is in totally random order. No time to fix it.)
- SyntaxError exceptions detected during code generation
(e.g. assignment to an expression) now include a line number.
- Don't leave trailing / or \ in script directory inserted in front of
sys.path.
- Added a note to Tools/scripts/classfix.py abouts its historical
importance.
- Added Misc/Makefile.pre.in, a universal Makefile for extensions
built outside the distribution.
- Rewritten Misc/faq2html.py, by Ka-Ping Yee.
- Install shared modules with mode 555 (needed for performance on some
platforms).
- Some changes to standard library modules to avoid calling append()
with more than one argument -- while supported, this should be
outlawed, and I don't want to set a bad example.
- bdb.py (and hence pdb.py) supports calling run() with a code object
instead of a code string.
- Fixed an embarrassing bug cgi.py which prevented correct uploading
of binary files from Netscape (which doesn't distinguish between
binary and text files). Also added dormant logging support, which
makes it easier to debug the cgi module itself.
- Added default writer to constructor of NullFormatter class.
- Use binary mode for socket.makefile() calls in ftplib.py.
- The ihooks module no longer "installs" itself upon import -- this
was an experimental feature that helped ironing out some bugs but that
slowed down code that imported it without the need to install it
(e.g. the rexec module). Also close the file in some cases and add
the __file__ attribute to loaded modules.
- The test program for mailbox.py is now more useful.
- Added getparamnames() to Message class in mimetools.py -- it returns
the names of parameters to the content-type header.
- Fixed a typo in ni that broke the loop stripping "__." from names.
- Fix sys.path[0] for scripts run via pdb.py's new main program.
- profile.py can now also run a script, like pdb.
- Fix a small bug in pyclbr -- don't add names starting with _ when
emulating from ... import *.
- Fixed a series of embarrassing typos in rexec's handling of standard
I/O redirection. Added some more "safe" built-in modules: cmath,
errno, operator.
- Fixed embarrassing typo in shelve.py.
- Added SliceType and EllipsisType to types.py.
- In urllib.py, added handling for error 301 (same as 302); added
geturl() method to get the URL after redirection.
- Fixed embarrassing typo in xdrlib.py. Also fixed typo in Setup.in
for _xdrmodule.c and removed redundant #include from _xdrmodule.c.
- Fixed bsddbmodule.c to add binary mode indicator on platforms that
have it. This should make it working on Windows NT.
- Changed last uses of #ifdef NT to #ifdef MS_WINDOWS or MS_WIN32,
whatever applies. Also rationalized some other tests for various MS
platforms.
- Added the sources for the NT installer script used for Python
1.4beta3. Not tested with this release, but better than nothing.
- A compromise in pickle's defenses against Trojan horses: a
user-defined function is now okay where a class is expected. A
built-in function is not okay, to prevent pickling something that
will execute os.system("rm -f *") when unpickling.
- dis.py will print the name of local variables referenced by local
load/store/delete instructions.
- Improved portability of SimpleHTTPServer module to non-Unix
platform.
- The thread.h interface adds an extra argument to down_sema(). This
only affects other C code that uses thread.c; the Python thread module
doesn't use semaphores (which aren't provided on all platforms where
Python threads are supported). Note: on NT, this change is not
implemented.
- Fixed some typos in abstract.h; corrected signature of
PyNumber_Coerce, added PyMapping_DelItem. Also fixed a bug in
abstract.c's PyObject_CallMethod().
- apply(classname, (), {}) now works even if the class has no
__init__() method.
- Implemented complex remainder and divmod() (these would dump core!).
Conversion of complex numbers to int, long int or float now raises an
exception, since there is no meaningful way to do it without losing
information.
- Fixed bug in built-in complex() function which gave the wrong result
for two real arguments.
- Change the hash algorithm for strings -- the multiplier is now
1000003 instead of 3, which gives better spread for short strings.
- New default path for Windows NT, the registry structure now supports
default paths for different install packages. (Mark Hammond -- the
next PythonWin release will use this.)
- Added more symbols to the python_nt.def file.
- When using GNU readline, set rl_readline_name to "python".
- The Ellipses built-in name has been renamed to Ellipsis -- this is
the correct singular form. Thanks to Ka-Ping Yee, who saved us from
eternal embarrassment.
- Bumped the PYTHON_API_VERSION to 1006, due to the Ellipses ->
Ellipsis name change.
- Updated the library reference manual. Added documentation of
restricted mode (rexec, Bastion) and the formatter module (for use
with the htmllib module). Fixed the documentation of htmllib
(finally).
- The reference manual is now maintained in FrameMaker.
- Upgraded scripts Doc/partparse.py and Doc/texi2html.py.
- Slight improvements to Doc/Makefile.
- Added fcntl.lockf(). This should be used for Unix file locking
instead of the posixfile module; lockf() is more portable.
- The getopt module now supports long option names, thanks to Lars
Wizenius.
- Plenty of changes to Tkinter and Canvas, mostly due to Fred Drake
and Nils Fischbeck.
- Use more bits of time.time() in whrandom's default seed().
- Performance hack for regex module's regs attribute.
- Don't close already closed socket in socket module.
- Correctly handle separators containing embedded nulls in
strop.split, strop.find and strop.rfind. Also added more detail to
error message for strop.atoi and friends.
- Moved fallback definition for hypot() to Python/hypot.c.
- Added fallback definition for strdup, in Python/strdup.c.
- Fixed some bugs where a function would return 0 to indicate an error
where it should return -1.
- Test for error returned by time.localtime(), and rationalized its MS
tests.
- Added Modules/Setup.local file, which is processed after Setup.
- Corrected bug in toplevel Makefile.in -- execution of regen script
would not use the right PATH and PYTHONPATH.
- Various and sundry NeXT configuration changes (sigh).
- Support systems where libreadline needs neither termcap nor curses.
- Improved ld_so_aix script and python.exp file (for AIX).
- More stringent test for working <stdarg.h> in configure script.
- Removed Demo/www subdirectory -- it was totally out of date.
- Improved demos and docs for Fred Drake's parser module; fixed one
typo in the module itself.
=========================================
==> Release 1.4beta3 (August 26 1996) <==
=========================================
(XXX This is less readable that it should. I promise to restructure
it for the final 1.4 release.)
What's new in 1.4beta3 (since beta2)?
-------------------------------------
- Name mangling to implement a simple form of class-private variables.
A name of the form "__spam" can't easily be used outside the class.
(This was added in 1.4beta3, but left out of the 1.4beta3 release
message.)
- In urllib.urlopen(): HTTP URLs containing user:passwd@host are now
handled correctly when using a proxy server.
- In ntpath.normpath(): don't truncate to 8+3 format.
- In mimetools.choose_boundary(): don't die when getuid() or getpid()
aren't defined.
- Module urllib: some optimizations to (un)quoting.
- New module MimeWriter for writing MIME documents.
- More changes to formatter module.
- The freeze script works once again and is much more robust (using
sys.prefix etc.). It also supports a -o option to specify an
output directory.
- New module whichdb recognizes dbm, gdbm and bsddb/dbhash files.
- The Doc/Makefile targets have been reorganized somewhat to remove the
insistence on always generating PostScript.
- The texinfo to html filter (Doc/texi2html.py) has been improved somewhat.
- "errors.h" has been renamed to "pyerrors.h" to resolve a long-standing
name conflict on the Mac.
- Linking a module compiled with a different setting for Py_TRACE_REFS now
generates a linker error rather than a core dump.
- The cgi module has a new convenience function print_exception(), which
formats a python exception using HTML. It also fixes a bug in the
compatibility code and adds a dubious feature which makes it possible to
have two query strings, one in the URL and one in the POST data.
- A subtle change in the unpickling of class instances makes it possible
to unpickle in restricted execution mode, where the __dict__ attribute is
not available (but setattr() is).
- Documentation for os.path.splitext() (== posixpath.splitext()) has been
cleared up. It splits at the *last* dot.
- posixfile locking is now also correctly supported on AIX.
- The tempfile module once again honors an initial setting of tmpdir. It
now works on Windows, too.
- The traceback module has some new functions to extract, format and print
the active stack.
- Some translation functions in the urllib module have been made a little
less sluggish.
- The addtag_* methods for Canvas widgets in Tkinter as well as in the
separate Canvas class have been fixed so they actually do something
meaningful.
- A tiny _test() function has been added to Tkinter.py.
- A generic Makefile for dynamically loaded modules is provided in the Misc
subdirectory (Misc/gMakefile).
- A new version of python-mode.el for Emacs is provided. See
http://www.python.org/ftp/emacs/pmdetails.html for details. The
separate file pyimenu.el is no longer needed, imenu support is folded
into python-mode.el.
- The configure script can finally correctly find the readline library in a
non-standard location. The LDFLAGS variable is passed on the Makefiles
from the configure script.
- Shared libraries are now installed as programs (i.e. with executable
permission). This is required on HP-UX and won't hurt on other systems.
- The objc.c module is no longer part of the distribution. Objective-C
support may become available as contributed software on the ftp site.
- The sybase module is no longer part of the distribution. A much
improved sybase module is available as contributed software from the
ftp site.
- _tkinter is now compatible with Tcl 7.5 / Tk 4.1 patch1 on Windows and
Mac (don't use unpatched Tcl/Tk!). The default line in the Setup.in file
now links with Tcl 7.5 / Tk 4.1 rather than 7.4/4.0.
- In Setup, you can now write "*shared*" instead of "*noconfig*", and you
can use *.so and *.sl as shared libraries.
- Some more fidgeting for AIX shared libraries.
- The mpz module is now compatible with GMP 2.x. (Not tested by me.)
(Note -- a complete replacement by Niels Mo"ller, called gpmodule, is
available from the contrib directory on the ftp site.)
- A warning is written to sys.stderr when a __del__ method raises an
exception (formerly, such exceptions were completely ignored).
- The configure script now defines HAVE_OLD_CPP if the C preprocessor is
incapable of ANSI style token concatenation and stringification.
- All source files (except a few platform specific modules) are once again
compatible with K&R C compilers as well as ANSI compilers. In particular,
ANSI-isms have been removed or made conditional in complexobject.c,
getargs.c and operator.c.
- The abstract object API has three new functions, PyObject_DelItem,
PySequence_DelItem, and PySequence_DelSlice.
- The operator module has new functions delitem and delslice, and the
functions "or" and "and" are renamed to "or_" and "and_" (since "or" and
"and" are reserved words). ("__or__" and "__and__" are unchanged.)
- The environment module is no longer supported; putenv() is now a function
in posixmodule (also under NT).
- Error in filter(<function>, "") has been fixed.
- Unrecognized keyword arguments raise TypeError, not KeyError.
- Better portability, fewer bugs and memory leaks, fewer compiler warnings,
some more documentation.
- Bug in float power boundary case (0.0 to the negative integer power)
fixed.
- The test of negative number to the float power has been moved from the
built-in pow() functin to floatobject.c (so complex numbers can yield the
correct result).
- The bug introduced in beta2 where shared libraries loaded (using
dlopen()) from the current directory would fail, has been fixed.
- Modules imported as shared libraries now also have a __file__ attribute,
giving the filename from which they were loaded. The only modules without
a __file__ attribute now are built-in modules.
- On the Mac, dynamically loaded modules can end in either ".slb" or
".<platform>.slb" where <platform> is either "CFM68K" or "ppc". The ".slb"
extension should only be used for "fat" binaries.
- C API addition: marshal.c now supports
PyMarshal_WriteObjectToString(object).
- C API addition: getargs.c now supports
PyArg_ParseTupleAndKeywords(args, kwdict, format, kwnames, ...)
to parse keyword arguments.
- The PC versioning scheme (sys.winver) has changed once again. the
version number is now "<digit>.<digit>.<digit>.<apiversion>", where the
first three <digit>s are the Python version (e.g. "1.4.0" for Python 1.4,
"1.4.1" for Python 1.4.1 -- the beta level is not included) and
<apiversion> is the four-digit PYTHON_API_VERSION (currently 1005).
- h2py.py accepts whitespace before the # in CPP directives
- On Solaris 2.5, it should now be possible to use either Posix threads or
Solaris threads (XXX: how do you select which is used???). (Note: the
Python pthreads interface doesn't fully support semaphores yet -- anyone
care to fix this?)
- Thread support should now work on AIX, using either DCE threads or
pthreads.
- New file Demo/sockets/unicast.py
- Working Mac port, with CFM68K support, with Tk 4.1 support (though not
both) (XXX)
- New project setup for PC port, now compatible with PythonWin, with
_tkinter and NumPy support (XXX)
- New module site.py (XXX)
- New module xdrlib.py and optional support module _xdrmodule.c (XXX)
- parser module adapted to new grammar, complete w/ Doc & Demo (XXX)
- regen script fixed (XXX)
- new machdep subdirectories Lib/{aix3,aix4,next3_3,freebsd2,linux2} (XXX)
- testall now also tests math module (XXX)
- string.atoi c.s. now raise an exception for an empty input string.
- At last, it is no longer necessary to define HAVE_CONFIG_H in order to
have config.h included at various places.
- Unrecognized keyword arguments now raise TypeError rather than KeyError.
- The makesetup script recognizes files with extension .so or .sl as
(shared) libraries.
- 'access' is no longer a reserved word, and all code related to its
implementation is gone (or at least #ifdef'ed out). This should make
Python a little speedier too!
- Performance enhancements suggested by Sjoerd Mullender. This includes
the introduction of two new optional function pointers in type object,
getattro and setattro, which are like getattr and setattr but take a
string object instead of a C string pointer.
- New operations in string module: lstrip(s) and rstrip(s) strip whitespace
only on the left or only on the right, A new optional third argument to
split() specifies the maximum number of separators honored (so
splitfields(s, sep, n) returns a list of at most n+1 elements). (Since
1.3, splitfields(s, None) is totally equivalent to split(s).)
string.capwords() has an optional second argument specifying the
separator (which is passed to split()).
- regsub.split() has the same addition as string.split(). regsub.splitx(s,
sep, maxsep) implements the functionality that was regsub.split(s, 1) in
1.4beta2 (return a list containing the delimiters as well as the words).
- Final touch for AIX loading, rewritten Misc/AIX-NOTES.
- In Modules/_tkinter.c, when using Tk 4.1 or higher, use className
argument to _tkinter.create() to set Tcl's argv0 variable, so X
resources use the right resource class again.
- Add #undef fabs to Modules/mathmodule.c for macintosh.
- Added some macro renames for AIX in Modules/operator.c.
- Removed spurious 'E' from Doc/liberrno.tex.
- Got rid of some cruft in Misc/ (dlMakefile, pyimenu.el); added new
Misc/gMakefile and new version of Misc/python-mode.el.
- Fixed typo in Lib/ntpath.py (islink has "return false" which gives a
NameError).
- Added missing "from types import *" to Lib/tkinter/Canvas.py.
- Added hint about using default args for __init__ to pickle docs.
- Corrected typo in Inclide/abstract.h: PySequence_Lenth ->
PySequence_Length.
- Some improvements to Doc/texi2html.py.
- In Python/import.c, Cast unsigned char * in struct _frozen to char *
in calls to rds_object().
- In doc/ref4.tex, added note about scope of lambda bodies.
What's new in 1.4beta2 (since beta1)?
-------------------------------------
- Portability bug in the md5.h header solved.
- The PC build procedure now really works, and sets sys.platform to a
meaningful value (a few things were botched in beta 1). Lib/dos_8x3
is now a standard part of the distribution (alas).
- More improvements to the installation procedure. Typing "make install"
now inserts the version number in the pathnames of almost everything
installed, and creates the machine dependent modules (FCNTL.py etc.) if not
supplied by the distribution. (XXX There's still a problem with the latter
because the "regen" script requires that Python is installed. Some manual
intervention may still be required.) (This has been fixed in 1.4beta3.)
- New modules: errno, operator (XXX).
- Changes for use with Numerical Python: builtin function slice() and
Ellipses object, and corresponding syntax:
x[lo:hi:stride] == x[slice(lo, hi, stride)]
x[a, ..., z] == x[(a, Ellipses, z)]
- New documentation for errno and cgi modules.
- The directory containing the script passed to the interpreter is
inserted in from of sys.path; "." is no longer a default path
component.
- Optional third string argument to string.translate() specifies
characters to delete. New function string.maketrans() creates a
translation table for translate() or for regex.compile().
- Module posix (and hence module os under Unix) now supports putenv().
Moreover, module os is enhanced so that if putenv() is supported,
assignments to os.environ entries make the appropriate putenv() call.
(XXX the putenv() implementation can leak a small amount of memory per
call.)
- pdb.py can now be invoked from the command line to debug a script:
python pdb.py <script> <arg> ...
- Much improved parseaddr() in rfc822.
- In cgi.py, you can now pass an alternative value for environ to
nearly all functions.
- You can now assign to instance variables whose name begins and ends
with '__'.
- New version of Fred Drake's parser module and associates (token,
symbol, AST).
- New PYTHON_API_VERSION value and .pyc file magic number (again!).
- The "complex" internal structure type is now called "Py_complex" to
avoid name conflicts.
- Numerous small bugs fixed.
- Slight pickle speedups.
- Some slight speedups suggested by Sjoerd (more coming in 1.4 final).
- NeXT portability mods by Bill Bumgarner integrated.
- Modules regexmodule.c, bsddbmodule.c and xxmodule.c have been
converted to new naming style.
What's new in 1.4beta1 (since 1.3)?
-----------------------------------
- Added sys.platform and sys.exec_platform for Bill Janssen.
- Installation has been completely overhauled. "make install" now installs
everything, not just the python binary. Installation uses the install-sh
script (borrowed from X11) to install each file.
- New functions in the posix module: mkfifo, plock, remove (== unlink),
and ftruncate. More functions are also available under NT.
- New function in the fcntl module: flock.
- Shared library support for FreeBSD.
- The --with-readline option can now be used without a DIRECTORY argument,
for systems where libreadline.* is in one of the standard places. It is
also possible for it to be a shared library.
- The extension tkinter has been renamed to _tkinter, to avoid confusion
with Tkinter.py oncase insensitive file systems. It now supports Tk 4.1 as
well as 4.0.
- Author's change of address from CWI in Amsterdam, The Netherlands, to
CNRI in Reston, VA, USA.
- The math.hypot() function is now always available (if it isn't found in
the C math library, Python provides its own implementation).
- The latex documentation is now compatible with latex2e, thanks to David
Ascher.
- The expression x**y is now equivalent to pow(x, y).
- The indexing expression x[a, b, c] is now equivalent to x[(a, b, c)].
- Complex numbers are now supported. Imaginary constants are written with
a 'j' or 'J' prefix, general complex numbers can be formed by adding a real
part to an imaginary part, like 3+4j. Complex numbers are always stored in
floating point form, so this is equivalent to 3.0+4.0j. It is also
possible to create complex numbers with the new built-in function
complex(re, [im]). For the footprint-conscious, complex number support can
be disabled by defining the symbol WITHOUT_COMPLEX.
- New built-in function list() is the long-awaited counterpart of tuple().
- There's a new "cmath" module which provides the same functions as the
"math" library but with complex arguments and results. (There are very
good reasons why math.sqrt(-1) still raises an exception -- you have to use
cmath.sqrt(-1) to get 1j for an answer.)
- The Python.h header file (which is really the same as allobjects.h except
it disables support for old style names) now includes several more files,
so you have to have fewer #include statements in the average extension.
- The NDEBUG symbol is no longer used. Code that used to be dependent on
the presence of NDEBUG is now present on the absence of DEBUG. TRACE_REFS
and REF_DEBUG have been renamed to Py_TRACE_REFS and Py_REF_DEBUG,
respectively. At long last, the source actually compiles and links without
errors when this symbol is defined.
- Several symbols that didn't follow the new naming scheme have been
renamed (usually by adding to rename2.h) to use a Py or _Py prefix. There
are no external symbols left without a Py or _Py prefix, not even those
defined by sources that were incorporated from elsewhere (regexpr.c,
md5c.c). (Macros are a different story...)
- There are now typedefs for the structures defined in config.c and
frozen.c.
- New PYTHON_API_VERSION value and .pyc file magic number.
- New module Bastion. (XXX)
- Improved performance of StringIO module.
- UserList module now supports + and * operators.
- The binhex and binascii modules now actually work.
- The cgi module has been almost totally rewritten and documented.
It now supports file upload and a new data type to handle forms more
flexibly.
- The formatter module (for use with htmllib) has been overhauled (again).
- The ftplib module now supports passive mode and has doc strings.
- In (ideally) all places where binary files are read or written, the file
is now correctly opened in binary mode ('rb' or 'wb') so the code will work
on Mac or PC.
- Dummy versions of os.path.expandvars() and expanduser() are now provided
on non-Unix platforms.
- Module urllib now has two new functions url2pathname and pathname2url
which turn local filenames into "file:..." URLs using the same rules as
Netscape (why be different). it also supports urlretrieve() with a
pathname parameter, and honors the proxy environment variables (http_proxy
etc.). The URL parsing has been improved somewhat, too.
- Micro improvements to urlparse. Added urlparse.urldefrag() which
removes a trailing ``#fragment'' if any.
- The mailbox module now supports MH style message delimiters as well.
- The mhlib module contains some new functionality: setcontext() to set the
current folder and parsesequence() to parse a sequence as commonly passed
to MH commands (e.g. 1-10 or last:5).
- New module mimify for conversion to and from MIME format of email
messages.
- Module ni now automatically installs itself when first imported -- this
is against the normal rule that modules should define classes and functions
but not invoke them, but appears more useful in the case that two
different, independent modules want to use ni's features.
- Some small performance enhancements in module pickle.
- Small interface change to the profile.run*() family of functions -- more
sensible handling of return values.
- The officially registered Mac creator for Python files is 'Pyth'. This
replaces 'PYTH' which was used before but never registered.
- Added regsub.capwords(). (XXX)
- Added string.capwords(), string.capitalize() and string.translate().
(XXX)
- Fixed an interface bug in the rexec module: it was impossible to pass a
hooks instance to the RExec class. rexec now also supports the dynamic
loading of modules from shared libraries. Some other interfaces have been
added too.
- Module rfc822 now caches the headers in a dictionary for more efficient
lookup.
- The sgmllib module now understands a limited number of SGML "shorthands"
like <A/.../ for <A>...</A>. (It's not clear that this was a good idea...)
- The tempfile module actually tries a number of different places to find a
usable temporary directory. (This was prompted by certain Linux
installations that appear to be missing a /usr/tmp directory.) [A bug in
the implementation that would ignore a pre-existing tmpdir global has been
fixed in beta3.]
- Much improved and enhanved FileDialog module for Tkinter.
- Many small changes to Tkinter, to bring it more in line with Tk 4.0 (as
well as Tk 4.1).
- New socket interfaces include ntohs(), ntohl(), htons(), htonl(), and
s.dup(). Sockets now work correctly on Windows. On Windows, the built-in
extension is called _socket and a wrapper module win/socket.py provides
"makefile()" and "dup()" functionality. On Windows, the select module
works only with socket objects.
- Bugs in bsddb module fixed (e.g. missing default argument values).
- The curses extension now includes <ncurses.h> when available.
- The gdbm module now supports opening databases in "fast" mode by
specifying 'f' as the second character or the mode string.
- new variables sys.prefix and sys.exec_prefix pass corresponding
configuration options / Makefile variables to the Python programmer.
- The ``new'' module now supports creating new user-defined classes as well
as instances thereof.
- The soundex module now sports get_soundex() to get the soundex value for an
arbitrary string (formerly it would only do soundex-based string
comparison) as well as doc strings.
- New object type "cobject" to safely wrap void pointers for passing them
between various extension modules.
- More efficient computation of float**smallint.
- The mysterious bug whereby "x.x" (two occurrences of the same
one-character name) typed from the commandline would sometimes fail
mysteriously.
- The initialization of the readline function can now be invoked by a C
extension through PyOS_ReadlineInit().
- There's now an externally visible pointer PyImport_FrozenModules which
can be changed by an embedding application.
- The argument parsing functions now support a new format character 'D' to
specify complex numbers.
- Various memory leaks plugged and bugs fixed.
- Improved support for posix threads (now that real implementations are
beginning to apepar). Still no fully functioning semaphores.
- Some various and sundry improvements and new entries in the Tools
directory.
=====================================
==> Release 1.3 (13 October 1995) <==
=====================================
Major change
============
Two words: Keyword Arguments. See the first section of Chapter 12 of
the Tutorial.
(The rest of this file is textually the same as the remaining sections
of that chapter.)
Changes to the WWW and Internet tools
=====================================
The "htmllib" module has been rewritten in an incompatible fashion.
The new version is considerably more complete (HTML 2.0 except forms,
but including all ISO-8859-1 entity definitions), and easy to use.
Small changes to "sgmllib" have also been made, to better match the
tokenization of HTML as recognized by other web tools.
A new module "formatter" has been added, for use with the new
"htmllib" module.
The "urllib"and "httplib" modules have been changed somewhat to allow
overriding unknown URL types and to support authentication. They now
use "mimetools.Message" instead of "rfc822.Message" to parse headers.
The "endrequest()" method has been removed from the HTTP class since
it breaks the interaction with some servers.
The "rfc822.Message" class has been changed to allow a flag to be
passed in that says that the file is unseekable.
The "ftplib" module has been fixed to be (hopefully) more robust on
Linux.
Several new operations that are optionally supported by servers have
been added to "nntplib": "xover", "xgtitle", "xpath" and "date".
Other Language Changes
======================
The "raise" statement now takes an optional argument which specifies
the traceback to be used when printing the exception's stack trace.
This must be a traceback object, such as found in "sys.exc_traceback".
When omitted or given as "None", the old behavior (to generate a stack
trace entry for the current stack frame) is used.
The tokenizer is now more tolerant of alien whitespace. Control-L in
the leading whitespace of a line resets the column number to zero,
while Control-R just before the end of the line is ignored.
Changes to Built-in Operations
==============================
For file objects, "f.read(0)" and "f.readline(0)" now return an empty
string rather than reading an unlimited number of bytes. For the
latter, omit the argument altogether or pass a negative value.
A new system variable, "sys.platform", has been added. It specifies
the current platform, e.g. "sunos5" or "linux1".
The built-in functions "input()" and "raw_input()" now use the GNU
readline library when it has been configured (formerly, only
interactive input to the interpreter itself was read using GNU
readline). The GNU readline library provides elaborate line editing
and history. The Python debugger ("pdb") is the first beneficiary of
this change.
Two new built-in functions, "globals()" and "locals()", provide access
to dictionaries containming current global and local variables,
respectively. (These augment rather than replace "vars()", which
returns the current local variables when called without an argument,
and a module's global variables when called with an argument of type
module.)
The built-in function "compile()" now takes a third possible value for
the kind of code to be compiled: specifying "'single'" generates code
for a single interactive statement, which prints the output of
expression statements that evaluate to something else than "None".
Library Changes
===============
There are new module "ni" and "ihooks" that support importing modules
with hierarchical names such as "A.B.C". This is enabled by writing
"import ni; ni.ni()" at the very top of the main program. These
modules are amply documented in the Python source.
The module "rexec" has been rewritten (incompatibly) to define a class
and to use "ihooks".
The "string.split()" and "string.splitfields()" functions are now the
same function (the presence or absence of the second argument
determines which operation is invoked); similar for "string.join()"
and "string.joinfields()".
The "Tkinter" module and its helper "Dialog" have been revamped to use
keyword arguments. Tk 4.0 is now the standard. A new module
"FileDialog" has been added which implements standard file selection
dialogs.
The optional built-in modules "dbm" and "gdbm" are more coordinated
--- their "open()" functions now take the same values for their "flag"
argument, and the "flag" and "mode" argument have default values (to
open the database for reading only, and to create the database with
mode "0666" minuse the umask, respectively). The memory leaks have
finally been fixed.
A new dbm-like module, "bsddb", has been added, which uses the BSD DB
package's hash method.
A portable (though slow) dbm-clone, implemented in Python, has been
added for systems where none of the above is provided. It is aptly
dubbed "dumbdbm".
The module "anydbm" provides a unified interface to "bsddb", "gdbm",
"dbm", and "dumbdbm", choosing the first one available.
A new extension module, "binascii", provides a variety of operations
for conversion of text-encoded binary data.
There are three new or rewritten companion modules implemented in
Python that can encode and decode the most common such formats: "uu"
(uuencode), "base64" and "binhex".
A module to handle the MIME encoding quoted-printable has also been
added: "quopri".
The parser module (which provides an interface to the Python parser's
abstract syntax trees) has been rewritten (incompatibly) by Fred
Drake. It now lets you change the parse tree and compile the result!
The \code{syslog} module has been upgraded and documented.
Other Changes
=============
The dynamic module loader recognizes the fact that different filenames
point to the same shared library and loads the library only once, so
you can have a single shared library that defines multiple modules.
(SunOS / SVR4 style shared libraries only.)
Jim Fulton's ``abstract object interface'' has been incorporated into
the run-time API. For more detailes, read the files
"Include/abstract.h" and "Objects/abstract.c".
The Macintosh version is much more robust now.
Numerous things I have forgotten or that are so obscure no-one will
notice them anyway :-)
===================================
==> Release 1.2 (13 April 1995) <==
===================================
- Changes to Misc/python-mode.el:
- Wrapping and indentation within triple quote strings should work
properly now.
- `Standard' bug reporting mechanism (use C-c C-b)
- py-mark-block was moved to C-c C-m
- C-c C-v shows you the python-mode version
- a basic python-font-lock-keywords has been added for Emacs 19
font-lock colorizations.
- proper interaction with pending-del and del-sel modes.
- New py-electric-colon (:) command for improved outdenting. Also
py-indent-line (TAB) should handle outdented lines better.
- New commands py-outdent-left (C-c C-l) and py-indent-right (C-c C-r)
- The Library Reference has been restructured, and many new and
existing modules are now documented, in particular the debugger and
the profiler, as well as the persistency and the WWW/Internet support
modules.
- All known bugs have been fixed. For example the pow(2,2,3L) bug on
Linux has been fixed. Also the re-entrancy problems with __del__ have
been fixed.
- All known memory leaks have been fixed.
- Phase 2 of the Great Renaming has been executed. The header files
now use the new names (PyObject instead of object, etc.). The linker
also sees the new names. Most source files still use the old names,
by virtue of the rename2.h header file. If you include Python.h, you
only see the new names. Dynamically linked modules have to be
recompiled. (Phase 3, fixing the rest of the sources, will be
executed gradually with the release later versions.)
- The hooks for implementing "safe-python" (better called "restricted
execution") are in place. Specifically, the import statement is
implemented by calling the built-in function __import__, and the
built-in names used in a particular scope are taken from the
dictionary __builtins__ in that scope's global dictionary. See also
the new (unsupported, undocumented) module rexec.py.
- The import statement now supports the syntax "import a.b.c" and
"from a.b.c import name". No officially supported implementation
exists, but one can be prototyped by replacing the built-in __import__
function. A proposal by Ken Manheimer is provided as newimp.py.
- All machinery used by the import statement (or the built-in
__import__ function) is now exposed through the new built-in module
"imp" (see the library reference manual). All dynamic loading
machinery is moved to the new file importdl.c.
- Persistent storage is supported through the use of the modules
"pickle" and "shelve" (implemented in Python). There's also a "copy"
module implementing deepcopy and normal (shallow) copy operations.
See the library reference manual.
- Documentation strings for many objects types are accessible through
the __doc__ attribute. Modules, classes and functions support special
syntax to initialize the __doc__ attribute: if the first statement
consists of just a string literal, that string literal becomes the
value of the __doc__ attribute. The default __doc__ attribute is
None. Documentation strings are also supported for built-in
functions, types and modules; however this feature hasn't been widely
used yet. See the 'new' module for an example. (Basically, the type
object's tp_doc field contains the doc string for the type, and the
4th member of the methodlist structure contains the doc string for the
method.)
- The __coerce__ and __cmp__ methods for user-defined classes once
again work as expected. As an example, there's a new standard class
Complex in the library.
- The functions posix.popen() and posix.fdopen() now have an optional
third argument to specify the buffer size, and default their second
(mode) argument to 'r' -- in analogy to the builtin open() function.
The same applies to posixfile.open() and the socket method makefile().
- The thread.exit_thread() function now raises SystemExit so that
'finally' clauses are honored and a memory leak is plugged.
- Improved X11 and Motif support, by Sjoerd Mullender. This extension
is being maintained and distributed separately.
- Improved support for the Apple Macintosh, in part by Jack Jansen,
e.g. interfaces to (a few) resource mananger functions, get/set file
type and creator, gestalt, sound manager, speech manager, MacTCP, comm
toolbox, and the think C console library. This is being maintained
and distributed separately.
- Improved version for Windows NT, by Mark Hammond. This is being
maintained and distributed separately.
- Used autoconf 2.0 to generate the configure script. Adapted
configure.in to use the new features in autoconf 2.0.
- It now builds on the NeXT without intervention, even on the 3.3
Sparc pre-release.
- Characters passed to isspace() and friends are masked to nonnegative
values.
- Correctly compute pow(-3.0, 3).
- Fix portability problems with getopt (configure now checks for a
non-GNU getopt).
- Don't add frozenmain.o to libPython.a.
- Exceptions can now be classes. ALl built-in exceptions are still
string objects, but this will change in the future.
- The socket module exports a long list of socket related symbols.
(More built-in modules will export their symbolic constants instead of
relying on a separately generated Python module.)
- When a module object is deleted, it clears out its own dictionary.
This fixes a circularity in the references between functions and
their global dictionary.
- Changed the error handling by [new]getargs() e.g. for "O&".
- Dynamic loading of modules using shared libraries is supported for
several new platforms.
- Support "O&", "[...]" and "{...}" in mkvalue().
- Extension to findmethod(): findmethodinchain() (where a chain is a
linked list of methodlist arrays). The calling interface for
findmethod() has changed: it now gets a pointer to the (static!)
methodlist structure rather than just to the function name -- this
saves copying flags etc. into the (short-lived) method object.
- The callable() function is now public.
- Object types can define a few new operations by setting function
pointers in the type object structure: tp_call defines how an object
is called, and tp_str defines how an object's str() is computed.
===================================
==> Release 1.1.1 (10 Nov 1994) <==
===================================
This is a pure bugfix release again. See the ChangeLog file for details.
One exception: a few new features were added to tkinter.
=================================
==> Release 1.1 (11 Oct 1994) <==
=================================
This release adds several new features, improved configuration and
portability, and fixes more bugs than I can list here (including some
memory leaks).
The source compiles and runs out of the box on more platforms than
ever -- including Windows NT. Makefiles or projects for a variety of
non-UNIX platforms are provided.
APOLOGY: some new features are badly documented or not at all. I had
the choice -- postpone the new release indefinitely, or release it
now, with working code but some undocumented areas. The problem with
postponing the release is that people continue to suffer from existing
bugs, and send me patches based on the previous release -- which I
can't apply directly because my own source has changed. Also, some
new modules (like signal) have been ready for release for quite some
time, and people are anxiously waiting for them. In the case of
signal, the interface is simple enough to figure out without
documentation (if you're anxious enough :-). In this case it was not
simple to release the module on its own, since it relies on many small
patches elsewhere in the source.
For most new Python modules, the source code contains comments that
explain how to use them. Documentation for the Tk interface, written
by Matt Conway, is available as tkinter-doc.tar.gz from the Python
home and mirror ftp sites (see Misc/FAQ for ftp addresses). For the
new operator overloading facilities, have a look at Demo/classes:
Complex.py and Rat.py show how to implement a numeric type without and
with __coerce__ method. Also have a look at the end of the Tutorial
document (Doc/tut.tex). If you're still confused: use the newsgroup
or mailing list.
New language features:
- More flexible operator overloading for user-defined classes
(INCOMPATIBLE WITH PREVIOUS VERSIONS!) See end of tutorial.
- Classes can define methods named __getattr__, __setattr__ and
__delattr__ to trap attribute accesses. See end of tutorial.
- Classes can define method __call__ so instances can be called
directly. See end of tutorial.
New support facilities:
- The Makefiles (for the base interpreter as well as for extensions)
now support creating dynamically loadable modules if the platform
supports shared libraries.
- Passing the interpreter a .pyc file as script argument will execute
the code in that file. (On the Mac such files can be double-clicked!)
- New Freeze script, to create independently distributable "binaries"
of Python programs -- look in Demo/freeze
- Improved h2py script (in Demo/scripts) follows #includes and
supports macros with one argument
- New module compileall generates .pyc files for all modules in a
directory (tree) without also executing them
- Threads should work on more platforms
New built-in modules:
- tkinter (support for Tcl's Tk widget set) is now part of the base
distribution
- signal allows catching or ignoring UNIX signals (unfortunately still
undocumented -- any taker?)
- termios provides portable access to POSIX tty settings
- curses provides an interface to the System V curses library
- syslog provides an interface to the (BSD?) syslog daemon
- 'new' provides interfaces to create new built-in object types
(e.g. modules and functions)
- sybase provides an interface to SYBASE database
New/obsolete built-in methods:
- callable(x) tests whether x can be called
- sockets now have a setblocking() method
- sockets no longer have an allowbroadcast() method
- socket methods send() and sendto() return byte count
New standard library modules:
- types.py defines standard names for built-in types, e.g. StringType
- urlparse.py parses URLs according to the latest Internet draft
- uu.py does uuencode/uudecode (not the fastest in the world, but
quicker than installing uuencode on a non-UNIX machine :-)
- New, faster and more powerful profile module.py
- mhlib.py provides interface to MH folders and messages
New facilities for extension writers (unfortunately still
undocumented):
- newgetargs() supports optional arguments and improved error messages
- O!, O& O? formats for getargs allow more versatile type checking of
non-standard types
- can register pending asynchronous callback, to be called the next
time the Python VM begins a new instruction (Py_AddPendingCall)
- can register cleanup routines to be called when Python exits
(Py_AtExit)
- makesetup script understands C++ files in Setup file (use file.C
or file.cc)
- Make variable OPT is passed on to sub-Makefiles
- An init<module>() routine may signal an error by not entering
the module in the module table and raising an exception instead
- For long module names, instead of foobarbletchmodule.c you can
use foobarbletch.c
- getintvalue() and getfloatvalue() try to convert any object
instead of requiring an "intobject" or "floatobject"
- All the [new]getargs() formats that retrieve an integer value
will now also work if a float is passed
- C function listtuple() converts list to tuple, fast
- You should now call sigcheck() instead of intrcheck();
sigcheck() also sets an exception when it returns nonzero
====================================
==> Release 1.0.3 (14 July 1994) <==
====================================
This release consists entirely of bug fixes to the C sources; see the
head of ../ChangeLog for a complete list. Most important bugs fixed:
- Sometimes the format operator (string%expr) would drop the last
character of the format string
- Tokenizer looped when last line did not end in \n
- Bug when triple-quoted string ended in quote plus newline
- Typo in socketmodule (listen) (== instead of =)
- typing vars() at the >>> prompt would cause recursive output
==================================
==> Release 1.0.2 (4 May 1994) <==
==================================
Overview of the most visible changes. Bug fixes are not listed. See
also ChangeLog.
Tokens
------
* String literals follow Standard C rules: they may be continued on
the next line using a backslash; adjacent literals are concatenated
at compile time.
* A new kind of string literals, surrounded by triple quotes (""" or
'''), can be continued on the next line without a backslash.
Syntax
------
* Function arguments may have a default value, e.g. def f(a, b=1);
defaults are evaluated at function definition time. This also applies
to lambda.
* The try-except statement has an optional else clause, which is
executed when no exception occurs in the try clause.
Interpreter
-----------
* The result of a statement-level expression is no longer printed,
except_ for expressions entered interactively. Consequently, the -k
command line option is gone.
* The result of the last printed interactive expression is assigned to
the variable '_'.
* Access to implicit global variables has been speeded up by removing
an always-failing dictionary lookup in the dictionary of local
variables (mod suggested by Steve Makewski and Tim Peters).
* There is a new command line option, -u, to force stdout and stderr
to be unbuffered.
* Incorporated Steve Majewski's mods to import.c for dynamic loading
under AIX.
* Fewer chances of dumping core when trying to reload or re-import
static built-in, dynamically loaded built-in, or frozen modules.
* Loops over sequences now don't ask for the sequence's length when
they start, but try to access items 0, 1, 2, and so on until they hit
an IndexError. This makes it possible to create classes that generate
infinite or indefinite sequences a la Steve Majewski. This affects
for loops, the (not) in operator, and the built-in functions filter(),
map(), max(), min(), reduce().
Changed Built-in operations
---------------------------
* The '%' operator on strings (printf-style formatting) supports a new
feature (adapted from a patch by Donald Beaudry) to allow
'%(<key>)<format>' % {...} to take values from a dictionary by name
instead of from a tuple by position (see also the new function
vars()).
* The '%s' formatting operator is changed to accept any type and
convert it to a string using str().
* Dictionaries with more than 20,000 entries can now be created
(thanks to Steve Kirsch).
New Built-in Functions
----------------------
* vars() returns a dictionary containing the local variables; vars(m)
returns a dictionary containing the variables of module m. Note:
dir(x) is now equivalent to vars(x).keys().
Changed Built-in Functions
--------------------------
* open() has an optional third argument to specify the buffer size: 0
for unbuffered, 1 for line buffered, >1 for explicit buffer size, <0
for default.
* open()'s second argument is now optional; it defaults to "r".
* apply() now checks that its second argument is indeed a tuple.
New Built-in Modules
--------------------
Changed Built-in Modules
------------------------
The thread module no longer supports exit_prog().
New Python Modules
------------------
* Module addpack contains a standard interface to modify sys.path to
find optional packages (groups of related modules).
* Module urllib contains a number of functions to access
World-Wide-Web files specified by their URL.
* Module httplib implements the client side of the HTTP protocol used
by World-Wide-Web servers.
* Module gopherlib implements the client side of the Gopher protocol.
* Module mailbox (by Jack Jansen) contains a parser for UNIX and MMDF
style mailbox files.
* Module random contains various random distributions, e.g. gauss().
* Module lockfile locks and unlocks open files using fcntl (inspired
by a similar module by Andy Bensky).
* Module ntpath (by Jaap Vermeulen) implements path operations for
Windows/NT.
* Module test_thread (in Lib/test) contains a small test set for the
thread module.
Changed Python Modules
----------------------
* The string module's expandvars() function is now documented and is
implemented in Python (using regular expressions) instead of forking
off a shell process.
* Module rfc822 now supports accessing the header fields using the
mapping/dictionary interface, e.g. h['subject'].
* Module pdb now makes it possible to set a break on a function
(syntax: break <expression>, where <expression> yields a function
object).
Changed Demos
-------------
* The Demo/scripts/freeze.py script is working again (thanks to Jaap
Vermeulen).
New Demos
---------
* Demo/threads/Generator.py is a proposed interface for restartable
functions a la Tim Peters.
* Demo/scripts/newslist.py, by Quentin Stafford-Fraser, generates a
directory full of HTML pages which between them contain links to all
the newsgroups available on your server.
* Demo/dns contains a DNS (Domain Name Server) client.
* Demo/lutz contains miscellaneous demos by Mark Lutz (e.g. psh.py, a
nice enhanced Python shell!!!).
* Demo/turing contains a Turing machine by Amrit Prem.
Documentation
-------------
* Documented new language features mentioned above (but not all new
modules).
* Added a chapter to the Tutorial describing recent additions to
Python.
* Clarified some sentences in the reference manual,
e.g. break/continue, local/global scope, slice assignment.
Source Structure
----------------
* Moved Include/tokenizer.h to Parser/tokenizer.h.
* Added Python/getopt.c for systems that don't have it.
Emacs mode
----------
* Indentation of continuated lines is done more intelligently;
consequently the variable py-continuation-offset is gone.
========================================
==> Release 1.0.1 (15 February 1994) <==
========================================
* Many portability fixes should make it painless to build Python on
several new platforms, e.g. NeXT, SEQUENT, WATCOM, DOS, and Windows.
* Fixed test for <stdarg.h> -- this broke on some platforms.
* Fixed test for shared library dynalic loading -- this broke on SunOS
4.x using the GNU loader.
* Changed order and number of SVR4 networking libraries (it is now
-lsocket -linet -lnsl, if these libraries exist).
* Installing the build intermediate stages with "make libainstall" now
also installs config.c.in, Setup and makesetup, which are used by the
new Extensions mechanism.
* Improved README file contains more hints and new troubleshooting
section.
* The built-in module strop now defines fast versions of three more
functions of the standard string module: atoi(), atol() and atof().
The strop versions of atoi() and atol() support an optional second
argument to specify the base (default 10). NOTE: you don't have to
explicitly import strop to use the faster versions -- the string
module contains code to let versions from stop override the default
versions.
* There is now a working Lib/dospath.py for those who use Python under
DOS (or Windows). Thanks, Jaap!
* There is now a working Modules/dosmodule.c for DOS (or Windows)
system calls.
* Lib.os.py has been reorganized (making it ready for more operating
systems).
* Lib/ospath.py is now obsolete (use os.path instead).
* Many fixes to the tutorial to make it match Python 1.0. Thanks,
Tim!
* Fixed Doc/Makefile, Doc/README and various scripts there.
* Added missing description of fdopen to Doc/libposix.tex.
* Made cleanup() global, for the benefit of embedded applications.
* Added parsing of addresses and dates to Lib/rfc822.py.
* Small fixes to Lib/aifc.py, Lib/sunau.py, Lib/tzparse.py to make
them usable at all.
* New module Lib/wave.py reads RIFF (*.wav) audio files.
* Module Lib/filewin.py moved to Lib/stdwin/filewin.py where it
belongs.
* New options and comments for Modules/makesetup (used by new
Extension mechanism).
* Misc/HYPE contains text of announcement of 1.0.0 in comp.lang.misc
and elsewhere.
* Fixed coredump in filter(None, 'abcdefg').
=======================================
==> Release 1.0.0 (26 January 1994) <==
=======================================
As is traditional, so many things have changed that I can't pretend to
be complete in these release notes, but I'll try anyway :-)
Note that the very last section is labeled "remaining bugs".
Source organization and build process
-------------------------------------
* The sources have finally been split: instead of a single src
subdirectory there are now separate directories Include, Parser,
Grammar, Objects, Python and Modules. Other directories also start
with a capital letter: Misc, Doc, Lib, Demo.
* A few extensions (notably Amoeba and X support) have been moved to a
separate subtree Extensions, which is no longer in the core
distribution, but separately ftp'able as extensions.tar.Z. (The
distribution contains a placeholder Ext-dummy with a description of
the Extensions subtree as well as the most recent versions of the
scripts used there.)
* A few large specialized demos (SGI video and www) have been
moved to a separate subdirectory Demo2, which is no longer in the core
distribution, but separately ftp'able as demo2.tar.Z.
* Parts of the standard library have been moved to subdirectories:
there are now standard subdirectories stdwin, test, sgi and sun4.
* The configuration process has radically changed: I now use GNU
autoconf. This makes it much easier to build on new Unix flavors, as
well as fully supporting VPATH (if your Make has it). The scripts
Configure.py and Addmodule.sh are no longer needed. Many source files
have been adapted in order to work with the symbols that the configure
script generated by autoconf defines (or not); the resulting source is
much more portable to different C compilers and operating systems,
even non Unix systems (a Mac port was done in an afternoon). See the
toplevel README file for a description of the new build process.
* GNU readline (a slightly newer version) is now a subdirectory of the
Python toplevel. It is still not automatically configured (being
totally autoconf-unaware :-). One problem has been solved: typing
Control-C to a readline prompt will now work. The distribution no
longer contains a "super-level" directory (above the python toplevel
directory), and dl, dl-dld and GNU dld are no longer part of the
Python distribution (you can still ftp them from
ftp.cwi.nl:/pub/dynload).
* The DOS functions have been taken out of posixmodule.c and moved
into a separate file dosmodule.c.
* There's now a separate file version.c which contains nothing but
the version number.
* The actual main program is now contained in config.c (unless NO_MAIN
is defined); pythonmain.c now contains a function realmain() which is
called from config.c's main().
* All files needed to use the built-in module md5 are now contained in
the distribution. The module has been cleaned up considerably.
Documentation
-------------
* The library manual has been split into many more small latex files,
so it is easier to edit Doc/lib.tex file to create a custom library
manual, describing only those modules supported on your system. (This
is not automated though.)
* A fourth manual has been added, titled "Extending and Embedding the
Python Interpreter" (Doc/ext.tex), which collects information about
the interpreter which was previously spread over several files in the
misc subdirectory.
* The entire documentation is now also available on-line for those who
have a WWW browser (e.g. NCSA Mosaic). Point your browser to the URL
"http://www.cwi.nl/~guido/Python.html".
Syntax
------
* Strings may now be enclosed in double quotes as well as in single
quotes. There is no difference in interpretation. The repr() of
string objects will use double quotes if the string contains a single
quote and no double quotes. Thanks to Amrit Prem for these changes!
* There is a new keyword 'exec'. This replaces the exec() built-in
function. If a function contains an exec statement, local variable
optimization is not performed for that particular function, thus
making assignment to local variables in exec statements less
confusing. (As a consequence, os.exec and python.exec have been
renamed to execv.)
* There is a new keyword 'lambda'. An expression of the form
lambda <parameters> : <expression>
yields an anonymous function. This is really only syntactic sugar;
you can just as well define a local function using
def some_temporary_name(<parameters>): return <expression>
Lambda expressions are particularly useful in combination with map(),
filter() and reduce(), described below. Thanks to Amrit Prem for
submitting this code (as well as map(), filter(), reduce() and
xrange())!
Built-in functions
------------------
* The built-in module containing the built-in functions is called
__builtin__ instead of builtin.
* New built-in functions map(), filter() and reduce() perform standard
functional programming operations (though not lazily):
- map(f, seq) returns a new sequence whose items are the items from
seq with f() applied to them.
- filter(f, seq) returns a subsequence of seq consisting of those
items for which f() is true.
- reduce(f, seq, initial) returns a value computed as follows:
acc = initial
for item in seq: acc = f(acc, item)
return acc
* New function xrange() creates a "range object". Its arguments are
the same as those of range(), and when used in a for loop a range
objects also behaves identical. The advantage of xrange() over
range() is that its representation (if the range contains many
elements) is much more compact than that of range(). The disadvantage
is that the result cannot be used to initialize a list object or for
the "Python idiom" [RED, GREEN, BLUE] = range(3). On some modern
architectures, benchmarks have shown that "for i in range(...): ..."
actually executes *faster* than "for i in xrange(...): ...", but on
memory starved machines like PCs running DOS range(100000) may be just
too big to be represented at all...
* Built-in function exec() has been replaced by the exec statement --
see above.
The interpreter
---------------
* Syntax errors are now not printed to stderr by the parser, but
rather the offending line and other relevant information are packed up
in the SyntaxError exception argument. When the main loop catches a
SyntaxError exception it will print the error in the same format as
previously, but at the proper position in the stack traceback.
* You can now set a maximum to the number of traceback entries
printed by assigning to sys.tracebacklimit. The default is 1000.
* The version number in .pyc files has changed yet again.
* It is now possible to have a .pyc file without a corresponding .py
file. (Warning: this may break existing installations if you have an
old .pyc file lingering around somewhere on your module search path
without a corresponding .py file, when there is a .py file for a
module of the same name further down the path -- the new interpreter
will find the first .pyc file and complain about it, while the old
interpreter would ignore it and use the .py file further down.)
* The list sys.builtin_module_names is now sorted and also contains
the names of a few hardwired built-in modules (sys, __main__ and
__builtin__).
* A module can now find its own name by accessing the global variable
__name__. Assigning to this variable essentially renames the module
(it should also be stored under a different key in sys.modules).
A neat hack follows from this: a module that wants to execute a main
program when called as a script no longer needs to compare
sys.argv[0]; it can simply do "if __name__ == '__main__': main()".
* When an object is printed by the print statement, its implementation
of str() is used. This means that classes can define __str__(self) to
direct how their instances are printed. This is different from
__repr__(self), which should define an unambigous string
representation of the instance. (If __str__() is not defined, it
defaults to __repr__().)
* Functions and code objects can now be compared meaningfully.
* On systems supporting SunOS or SVR4 style shared libraries, dynamic
loading of modules using shared libraries is automatically configured.
Thanks to Bill Jansen and Denis Severson for contributing this change!
Built-in objects
----------------
* File objects have acquired a new method writelines() which is the
reverse of readlines(). (It does not actually write lines, just a
list of strings, but the symmetry makes the choice of name OK.)
Built-in modules
----------------
* Socket objects no longer support the avail() method. Use the select
module instead, or use this function to replace it:
def avail(f):
import select
return f in select.select([f], [], [], 0)[0]
* Initialization of stdwin is done differently. It actually modifies
sys.argv (taking out the options the X version of stdwin recognizes)
the first time it is imported.
* A new built-in module parser provides a rudimentary interface to the
python parser. Corresponding standard library modules token and symbol
defines the numeric values of tokens and non-terminal symbols.
* The posix module has aquired new functions setuid(), setgid(),
execve(), and exec() has been renamed to execv().
* The array module is extended with 8-byte object swaps, the 'i'
format character, and a reverse() method. The read() and write()
methods are renamed to fromfile() and tofile().
* The rotor module has freed of portability bugs. This introduces a
backward compatibility problem: strings encoded with the old rotor
module can't be decoded by the new version.
* For select.select(), a timeout (4th) argument of None means the same
as leaving the timeout argument out.
* Module strop (and hence standard library module string) has aquired
a new function: rindex(). Thanks to Amrit Prem!
* Module regex defines a new function symcomp() which uses an extended
regular expression syntax: parenthesized subexpressions may be labeled
using the form "\(<labelname>...\)", and the group() method can return
sub-expressions by name. Thanks to Tracy Tims for these changes!
* Multiple threads are now supported on Solaris 2. Thanks to Sjoerd
Mullender!
Standard library modules
------------------------
* The library is now split in several subdirectories: all stuff using
stdwin is in Lib/stdwin, all SGI specific (or SGI Indigo or GL) stuff
is in Lib/sgi, all Sun Sparc specific stuff is in Lib/sun4, and all
test modules are in Lib/test. The default module search path will
include all relevant subdirectories by default.
* Module os now knows about trying to import dos. It defines
functions execl(), execle(), execlp() and execvp().
* New module dospath (should be attacked by a DOS hacker though).
* All modules defining classes now define __init__() constructors
instead of init() methods. THIS IS AN INCOMPATIBLE CHANGE!
* Some minor changes and bugfixes module ftplib (mostly Steve
Majewski's suggestions); the debug() method is renamed to
set_debuglevel().
* Some new test modules (not run automatically by testall though):
test_audioop, test_md5, test_rgbimg, test_select.
* Module string now defines rindex() and rfind() in analogy of index()
and find(). It also defines atof() and atol() (and corresponding
exceptions) in analogy to atoi().
* Added help() functions to modules profile and pdb.
* The wdb debugger (now in Lib/stdwin) now shows class or instance
variables on a double click. Thanks to Sjoerd Mullender!
* The (undocumented) module lambda has gone -- you couldn't import it
any more, and it was basically more a demo than a library module...
Multimedia extensions
---------------------
* The optional built-in modules audioop and imageop are now standard
parts of the interpreter. Thanks to Sjoerd Mullender and Jack Jansen
for contributing this code!
* There's a new operation in audioop: minmax().
* There's a new built-in module called rgbimg which supports portable
efficient reading of SGI RCG image files. Thanks also to Paul
Haeberli for the original code! (Who will contribute a GIF reader?)
* The module aifc is gone -- you should now always use aifc, which has
received a facelift.
* There's a new module sunau., for reading Sun (and NeXT) audio files.
* There's a new module audiodev which provides a uniform interface to
(SGI Indigo and Sun Sparc) audio hardware.
* There's a new module sndhdr which recognizes various sound files by
looking in their header and checking for various magic words.
Optimizations
-------------
* Most optimizations below can be configured by compile-time flags.
Thanks to Sjoerd Mullender for submitting these optimizations!
* Small integers (default -1..99) are shared -- i.e. if two different
functions compute the same value it is possible (but not
guaranteed!!!) that they return the same *object*. Python programs
can detect this but should *never* rely on it.
* Empty tuples (which all compare equal) are shared in the same
manner.
* Tuples of size up to 20 (default) are put in separate free lists
when deallocated.
* There is a compile-time option to cache a string's hash function,
but this appeared to have a negligeable effect, and as it costs 4
bytes per string it is disabled by default.
Embedding Python
----------------
* The initialization interface has been simplified somewhat. You now
only call "initall()" to initialize the interpreter.
* The previously announced renaming of externally visible identifiers
has not been carried out. It will happen in a later release. Sorry.
Miscellaneous bugs that have been fixed
---------------------------------------
* All known portability bugs.
* Version 0.9.9 dumped core in <listobject>.sort() which has been
fixed. Thanks to Jaap Vermeulen for fixing this and posting the fix
on the mailing list while I was away!
* Core dump on a format string ending in '%', e.g. in the expression
'%' % None.
* The array module yielded a bogus result for concatenation (a+b would
yield a+a).
* Some serious memory leaks in strop.split() and strop.splitfields().
* Several problems with the nis module.
* Subtle problem when copying a class method from another class
through assignment (the method could not be called).
Remaining bugs
--------------
* One problem with 64-bit machines remains -- since .pyc files are
portable and use only 4 bytes to represent an integer object, 64-bit
integer literals are silently truncated when written into a .pyc file.
Work-around: use eval('123456789101112').
* The freeze script doesn't work any more. A new and more portable
one can probably be cooked up using tricks from Extensions/mkext.py.
* The dos support hasn't been tested yet. (Really Soon Now we should
have a PC with a working C compiler!)
===================================
==> Release 0.9.9 (29 Jul 1993) <==
===================================
I *believe* these are the main user-visible changes in this release,
but there may be others. SGI users may scan the {src,lib}/ChangeLog
files for improvements of some SGI specific modules, e.g. aifc and
cl. Developers of extension modules should also read src/ChangeLog.
Naming of C symbols used by the Python interpreter
--------------------------------------------------
* This is the last release using the current naming conventions. New
naming conventions are explained in the file misc/NAMING.
Summarizing, all externally visible symbols get (at least) a "Py"
prefix, and most functions are renamed to the standard form
PyModule_FunctionName.
* Writers of extensions are urged to start using the new naming
conventions. The next release will use the new naming conventions
throughout (it will also have a different source directory
structure).
* As a result of the preliminary work for the great renaming, many
functions that were accidentally global have been made static.
BETA X11 support
----------------
* There are now modules interfacing to the X11 Toolkit Intrinsics, the
Athena widgets, and the Motif 1.1 widget set. These are not yet
documented except through the examples and README file in the demo/x11
directory. It is expected that this interface will be replaced by a
more powerful and correct one in the future, which may or may not be
backward compatible. In other words, this part of the code is at most
BETA level software! (Note: the rest of Python is rock solid as ever!)
* I understand that the above may be a bit of a disappointment,
however my current schedule does not allow me to change this situation
before putting the release out of the door. By releasing it
undocumented and buggy, at least some of the (working!) demo programs,
like itr (my Internet Talk Radio browser) become available to a larger
audience.
* There are also modules interfacing to SGI's "Glx" widget (a GL
window wrapped in a widget) and to NCSA's "HTML" widget (which can
format HyperText Markup Language, the document format used by the
World Wide Web).
* I've experienced some problems when building the X11 support. In
particular, the Xm and Xaw widget sets don't go together, and it
appears that using X11R5 is better than using X11R4. Also the threads
module and its link time options may spoil things. My own strategy is
to build two Python binaries: one for use with X11 and one without
it, which can contain a richer set of built-in modules. Don't even
*think* of loading the X11 modules dynamically...
Environmental changes
---------------------
* Compiled files (*.pyc files) created by this Python version are
incompatible with those created by the previous version. Both
versions detect this and silently create a correct version, but it
means that it is not a good idea to use the same library directory for
an old and a new interpreter, since they will start to "fight" over
the *.pyc files...
* When a stack trace is printed, the exception is printed last instead
of first. This means that if the beginning of the stack trace
scrolled out of your window you can still see what exception caused
it.
* Sometimes interrupting a Python operation does not work because it
hangs in a blocking system call. You can now kill the interpreter by
interrupting it three times. The second time you interrupt it, a
message will be printed telling you that the third interrupt will kill
the interpreter. The "sys.exitfunc" feature still makes limited
clean-up possible in this case.
Changes to the command line interface
-------------------------------------
* The python usage message is now much more informative.
* New option -i enters interactive mode after executing a script --
useful for debugging.
* New option -k raises an exception when an expression statement
yields a value other than None.
* For each option there is now also a corresponding environment
variable.
Using Python as an embedded language
------------------------------------
* The distribution now contains (some) documentation on the use of
Python as an "embedded language" in other applications, as well as a
simple example. See the file misc/EMBEDDING and the directory embed/.
Speed improvements
------------------
* Function local variables are now generally stored in an array and
accessed using an integer indexing operation, instead of through a
dictionary lookup. (This compensates the somewhat slower dictionary
lookup caused by the generalization of the dictionary module.)
Changes to the syntax
---------------------
* Continuation lines can now *sometimes* be written without a
backslash: if the continuation is contained within nesting (), [] or
{} brackets the \ may be omitted. There's a much improved
python-mode.el in the misc directory which knows about this as well.
* You can no longer use an empty set of parentheses to define a class
without base classes. That is, you no longer write this:
class Foo(): # syntax error
...
You must write this instead:
class Foo:
...
This was already the preferred syntax in release 0.9.8 but many
people seemed not to have picked it up. There's a Python script that
fixes old code: demo/scripts/classfix.py.
* There's a new reserved word: "access". The syntax and semantics are
still subject of of research and debate (as well as undocumented), but
the parser knows about the keyword so you must not use it as a
variable, function, or attribute name.
Changes to the semantics of the language proper
-----------------------------------------------
* The following compatibility hack is removed: if a function was
defined with two or more arguments, and called with a single argument
that was a tuple with just as many arguments, the items of this tuple
would be used as the arguments. This is no longer supported.
Changes to the semantics of classes and instances
-------------------------------------------------
* Class variables are now also accessible as instance variables for
reading (assignment creates an instance variable which overrides the
class variable of the same name though).
* If a class attribute is a user-defined function, a new kind of
object is returned: an "unbound method". This contains a pointer to
the class and can only be called with a first argument which is a
member of that class (or a derived class).
* If a class defines a method __init__(self, arg1, ...) then this
method is called when a class instance is created by the classname()
construct. Arguments passed to classname() are passed to the
__init__() method. The __init__() methods of base classes are not
automatically called; the derived __init__() method must call these if
necessary (this was done so the derived __init__() method can choose
the call order and arguments for the base __init__() methods).
* If a class defines a method __del__(self) then this method is called
when an instance of the class is about to be destroyed. This makes it
possible to implement clean-up of external resources attached to the
instance. As with __init__(), the __del__() methods of base classes
are not automatically called. If __del__ manages to store a reference
to the object somewhere, its destruction is postponed; when the object
is again about to be destroyed its __del__() method will be called
again.
* Classes may define a method __hash__(self) to allow their instances
to be used as dictionary keys. This must return a 32-bit integer.
Minor improvements
------------------
* Function and class objects now know their name (the name given in
the 'def' or 'class' statement that created them).
* Class instances now know their class name.
Additions to built-in operations
--------------------------------
* The % operator with a string left argument implements formatting
similar to sprintf() in C. The right argument is either a single
value or a tuple of values. All features of Standard C sprintf() are
supported except %p.
* Dictionaries now support almost any key type, instead of just
strings. (The key type must be an immutable type or must be a class
instance where the class defines a method __hash__(), in order to
avoid losing track of keys whose value may change.)
* Built-in methods are now compared properly: when comparing x.meth1
and y.meth2, if x is equal to y and the methods are defined by the
same function, x.meth1 compares equal to y.meth2.
Additions to built-in functions
-------------------------------
* str(x) returns a string version of its argument. If the argument is
a string it is returned unchanged, otherwise it returns `x`.
* repr(x) returns the same as `x`. (Some users found it easier to
have this as a function.)
* round(x) returns the floating point number x rounded to an whole
number, represented as a floating point number. round(x, n) returns x
rounded to n digits.
* hasattr(x, name) returns true when x has an attribute with the given
name.
* hash(x) returns a hash code (32-bit integer) of an arbitrary
immutable object's value.
* id(x) returns a unique identifier (32-bit integer) of an arbitrary
object.
* compile() compiles a string to a Python code object.
* exec() and eval() now support execution of code objects.
Changes to the documented part of the library (standard modules)
----------------------------------------------------------------
* os.path.normpath() (a.k.a. posixpath.normpath()) has been fixed so
the border case '/foo/..' returns '/' instead of ''.
* A new function string.find() is added with similar semantics to
string.index(); however when it does not find the given substring it
returns -1 instead of raising string.index_error.
Changes to built-in modules
---------------------------
* New optional module 'array' implements operations on sequences of
integers or floating point numbers of a particular size. This is
useful to manipulate large numerical arrays or to read and write
binary files consisting of numerical data.
* Regular expression objects created by module regex now support a new
method named group(), which returns one or more \(...\) groups by number.
The number of groups is increased from 10 to 100.
* Function compile() in module regex now supports an optional mapping
argument; a variable casefold is added to the module which can be used
as a standard uppercase to lowercase mapping.
* Module time now supports many routines that are defined in the
Standard C time interface (<time.h>): gmtime(), localtime(),
asctime(), ctime(), mktime(), as well as these variables (taken from
System V): timezone, altzone, daylight and tzname. (The corresponding
functions in the undocumented module calendar have been removed; the
undocumented and unfinished module tzparse is now obsolete and will
disappear in a future release.)
* Module strop (the fast built-in version of standard module string)
now uses C's definition of whitespace instead of fixing it to space,
tab and newline; in practice this usually means that vertical tab,
form feed and return are now also considered whitespace. It exports
the string of characters that are considered whitespace as well as the
characters that are considered lowercase or uppercase.
* Module sys now defines the variable builtin_module_names, a list of
names of modules built into the current interpreter (including not
yet imported, but excluding two special modules that always have to be
defined -- sys and builtin).
* Objects created by module sunaudiodev now also support flush() and
close() methods.
* Socket objects created by module socket now support an optional
flags argument for their methods sendto() and recvfrom().
* Module marshal now supports dumping to and loading from strings,
through the functions dumps() and loads().
* Module stdwin now supports some new functionality. You may have to
ftp the latest version: ftp.cwi.nl:/pub/stdwin/stdwinforviews.tar.Z.)
Bugs fixed
----------
* Fixed comparison of negative long integers.
* The tokenizer no longer botches input lines longer than BUFSIZ.
* Fixed several severe memory leaks in module select.
* Fixed memory leaks in modules socket and sv.
* Fixed memory leak in divmod() for long integers.
* Problems with definition of floatsleep() on Suns fixed.
* Many portability bugs fixed (and undoubtedly new ones added :-).
Changes to the build procedure
------------------------------
* The Makefile supports some new targets: "make default" and "make
all". Both are by normally equivalent to "make python".
* The Makefile no longer uses $> since it's not supported by all
versions of Make.
* The header files now all contain #ifdef constructs designed to make
it safe to include the same header file twice, as well as support for
inclusion from C++ programs (automatic extern "C" { ... } added).
Freezing Python scripts
-----------------------
* There is now some support for "freezing" a Python script as a
stand-alone executable binary file. See the script
demo/scripts/freeze.py. It will require some site-specific tailoring
of the script to get this working, but is quite worthwhile if you write
Python code for other who may not have built and installed Python.
MS-DOS
------
* A new MS-DOS port has been done, using MSC 6.0 (I believe). Thanks,
Marcel van der Peijl! This requires fewer compatibility hacks in
posixmodule.c. The executable is not yet available but will be soon
(check the mailing list).
* The default PYTHONPATH has changed.
Changes for developers of extension modules
-------------------------------------------
* Read src/ChangeLog for full details.
SGI specific changes
--------------------
* Read src/ChangeLog for full details.
==================================
==> Release 0.9.8 (9 Jan 1993) <==
==================================
I claim no completeness here, but I've tried my best to scan the log
files throughout my source tree for interesting bits of news. A more
complete account of the changes is to be found in the various
ChangeLog files. See also "News for release 0.9.7beta" below if you're
still using release 0.9.6, and the file HISTORY if you have an even
older release.
--Guido
Changes to the language proper
------------------------------
There's only one big change: the conformance checking for function
argument lists (of user-defined functions only) is stricter. Earlier,
you could get away with the following:
(a) define a function of one argument and call it with any
number of arguments; if the actual argument count wasn't
one, the function would receive a tuple containing the
arguments arguments (an empty tuple if there were none).
(b) define a function of two arguments, and call it with more
than two arguments; if there were more than two arguments,
the second argument would be passed as a tuple containing
the second and further actual arguments.
(Note that an argument (formal or actual) that is a tuple is counted as
one; these rules don't apply inside such tuples, only at the top level
of the argument list.)
Case (a) was needed to accommodate variable-length argument lists;
there is now an explicit "varargs" feature (precede the last argument
with a '*'). Case (b) was needed for compatibility with old class
definitions: up to release 0.9.4 a method with more than one argument
had to be declared as "def meth(self, (arg1, arg2, ...)): ...".
Version 0.9.6 provide better ways to handle both casees, bot provided
backward compatibility; version 0.9.8 retracts the compatibility hacks
since they also cause confusing behavior if a function is called with
the wrong number of arguments.
There's a script that helps converting classes that still rely on (b),
provided their methods' first argument is called "self":
demo/scripts/methfix.py.
If this change breaks lots of code you have developed locally, try
#defining COMPAT_HACKS in ceval.c.
(There's a third compatibility hack, which is the reverse of (a): if a
function is defined with two or more arguments, and called with a
single argument that is a tuple with just as many arguments, the items
of this tuple will be used as the arguments. Although this can (and
should!) be done using the built-in function apply() instead, it isn't
withdrawn yet.)
One minor change: comparing instance methods works like expected, so
that if x is an instance of a user-defined class and has a method m,
then (x.m==x.m) yields 1.
The following was already present in 0.9.7beta, but not explicitly
mentioned in the NEWS file: user-defined classes can now define types
that behave in almost allrespects like numbers. See
demo/classes/Rat.py for a simple example.
Changes to the build process
----------------------------
The Configure.py script and the Makefile has been made somewhat more
bullet-proof, after reports of (minor) trouble on certain platforms.
There is now a script to patch Makefile and config.c to add a new
optional built-in module: Addmodule.sh. Read the script before using!
Useing Addmodule.sh, all optional modules can now be configured at
compile time using Configure.py, so there are no modules left that
require dynamic loading.
The Makefile has been fixed to make it easier to use with the VPATH
feature of some Make versions (e.g. SunOS).
Changes affecting portability
-----------------------------
Several minor portability problems have been solved, e.g. "malloc.h"
has been renamed to "mymalloc.h", "strdup.c" is no longer used, and
the system now tolerates malloc(0) returning 0.
For dynamic loading on the SGI, Jack Jansen's dl 1.6 is now
distributed with Python. This solves several minor problems, in
particular scripts invoked using #! can now use dynamic loading.
Changes to the interpreter interface
------------------------------------
On popular demand, there's finally a "profile" feature for interactive
use of the interpreter. If the environment variable $PYTHONSTARTUP is
set to the name of an existing file, Python statements in this file
are executed when the interpreter is started in interactive mode.
There is a new clean-up mechanism, complementing try...finally: if you
assign a function object to sys.exitfunc, it will be called when
Python exits or receives a SIGTERM or SIGHUP signal.
The interpreter is now generally assumed to live in
/usr/local/bin/python (as opposed to /usr/local/python). The script
demo/scripts/fixps.py will update old scripts in place (you can easily
modify it to do other similar changes).
Most I/O that uses sys.stdin/stdout/stderr will now use any object
assigned to those names as long as the object supports readline() or
write() methods.
The parser stack has been increased to 500 to accommodate more
complicated expressions (7 levels used to be the practical maximum,
it's now about 38).
The limit on the size of the *run-time* stack has completely been
removed -- this means that tuple or list displays can contain any
number of elements (formerly more than 50 would crash the
interpreter).
Changes to existing built-in functions and methods
--------------------------------------------------
The built-in functions int(), long(), float(), oct() and hex() now
also apply to class instalces that define corresponding methods
(__int__ etc.).
New built-in functions
----------------------
The new functions str() and repr() convert any object to a string.
The function repr(x) is in all respects equivalent to `x` -- some
people prefer a function for this. The function str(x) does the same
except if x is already a string -- then it returns x unchanged
(repr(x) adds quotes and escapes "funny" characters as octal escapes).
The new function cmp(x, y) returns -1 if x<y, 0 if x==y, 1 if x>y.
Changes to general built-in modules
-----------------------------------
The time module's functions are more general: time() returns a
floating point number and sleep() accepts one. Their accuracies
depends on the precision of the system clock. Millisleep is no longer
needed (although it still exists for now), but millitimer is still
needed since on some systems wall clock time is only available with
seconds precision, while a source of more precise time exists that
isn't synchronized with the wall clock. (On UNIX systems that support
the BSD gettimeofday() function, time.time() is as time.millitimer().)
The string representation of a file object now includes an address:
'<file 'filename', mode 'r' at #######>' where ###### is a hex number
(the object's address) to make it unique.
New functions added to posix: nice(), setpgrp(), and if your system
supports them: setsid(), setpgid(), tcgetpgrp(), tcsetpgrp().
Improvements to the socket module: socket objects have new methods
getpeername() and getsockname(), and the {get,set}sockopt methods can
now get/set any kind of option using strings built with the new struct
module. And there's a new function fromfd() which creates a socket
object given a file descriptor (useful for servers started by inetd,
which have a socket connected to stdin and stdout).
Changes to SGI-specific built-in modules
----------------------------------------
The FORMS library interface (fl) now requires FORMS 2.1a. Some new
functions have been added and some bugs have been fixed.
Additions to al (audio library interface): added getname(),
getdefault() and getminmax().
The gl modules doesn't call "foreground()" when initialized (this
caused some problems) like it dit in 0.9.7beta (but not before).
There's a new gl function 'gversion() which returns a version string.
The interface to sv (Indigo video interface) has totally changed.
(Sorry, still no documentation, but see the examples in
demo/sgi/{sv,video}.)
Changes to standard library modules
-----------------------------------
Most functions in module string are now much faster: they're actually
implemented in C. The module containing the C versions is called
"strop" but you should still import "string" since strop doesn't
provide all the interfaces defined in string (and strop may be renamed
to string when it is complete in a future release).
string.index() now accepts an optional third argument giving an index
where to start searching in the first argument, so you can find second
and further occurrences (this is similar to the regular expression
functions in regex).
The definition of what string.splitfields(anything, '') should return
is changed for the last time: it returns a singleton list containing
its whole first argument unchanged. This is compatible with
regsub.split() which also ignores empty delimiter matches.
posixpath, macpath: added dirname() and normpath() (and basename() to
macpath).
The mainloop module (for use with stdwin) can now demultiplex input
from other sources, as long as they can be polled with select().
New built-in modules
--------------------
Module struct defines functions to pack/unpack values to/from strings
representing binary values in native byte order.
Module strop implements C versions of many functions from string (see
above).
Optional module fcntl defines interfaces to fcntl() and ioctl() --
UNIX only. (Not yet properly documented -- see however src/fcntl.doc.)
Optional module mpz defines an interface to an altaernative long
integer implementation, the GNU MPZ library.
Optional module md5 uses the GNU MPZ library to calculate MD5
signatures of strings.
There are also optional new modules specific to SGI machines: imageop
defines some simple operations to images represented as strings; sv
interfaces to the Indigo video board; cl interfaces to the (yet
unreleased) compression library.
New standard library modules
----------------------------
(Unfortunately the following modules are not all documented; read the
sources to find out more about them!)
autotest: run testall without showing any output unless it differs
from the expected output
bisect: use bisection to insert or find an item in a sorted list
colorsys: defines conversions between various color systems (e.g. RGB
<-> YUV)
nntplib: a client interface to NNTP servers
pipes: utility to construct pipeline from templates, e.g. for
conversion from one file format to another using several utilities.
regsub: contains three functions that are more or less compatible with
awk functions of the same name: sub() and gsub() do string
substitution, split() splits a string using a regular expression to
define how separators are define.
test_types: test operations on the built-in types of Python
toaiff: convert various audio file formats to AIFF format
tzparse: parse the TZ environment parameter (this may be less general
than it could be, let me know if you fix it).
(Note that the obsolete module "path" no longer exists.)
New SGI-specific library modules
--------------------------------
CL: constants for use with the built-in compression library interface (cl)
Queue: a multi-producer, multi-consumer queue class implemented for
use with the built-in thread module
SOCKET: constants for use with built-in module socket, e.g. to set/get
socket options. This is SGI-specific because the constants to be
passed are system-dependent. You can generate a version for your own
system by running the script demo/scripts/h2py.py with
/usr/include/sys/socket.h as input.
cddb: interface to the database used by the CD player
torgb: convert various image file types to rgb format (requires pbmplus)
New demos
---------
There's an experimental interface to define Sun RPC clients and
servers in demo/rpc.
There's a collection of interfaces to WWW, WAIS and Gopher (both
Python classes and program providing a user interface) in demo/www.
This includes a program texi2html.py which converts texinfo files to
HTML files (the format used hy WWW).
The ibrowse demo has moved from demo/stdwin/ibrowse to demo/ibrowse.
For SGI systems, there's a whole collection of programs and classes
that make use of the Indigo video board in demo/sgi/{sv,video}. This
represents a significant amount of work that we're giving away!
There are demos "rsa" and "md5test" that exercise the mpz and md5
modules, respectively. The rsa demo is a complete implementation of
the RSA public-key cryptosystem!
A bunch of games and examples submitted by Stoffel Erasmus have been
included in demo/stoffel.
There are miscellaneous new files in some existing demo
subdirectories: classes/bitvec.py, scripts/{fixps,methfix}.py,
sgi/al/cmpaf.py, sockets/{mcast,gopher}.py.
There are also many minor changes to existing files, but I'm too lazy
to run a diff and note the differences -- you can do this yourself if
you save the old distribution's demos. One highlight: the
stdwin/python.py demo is much improved!
Changes to the documentation
----------------------------
The LaTeX source for the library uses different macros to enable it to
be converted to texinfo, and from there to INFO or HTML format so it
can be browsed as a hypertext. The net result is that you can now
read the Python library documentation in Emacs info mode!
Changes to the source code that affect C extension writers
----------------------------------------------------------
The function strdup() no longer exists (it was used only in one places
and is somewhat of a a portability problem sice some systems have the
same function in their C library.
The functions NEW() and RENEW() allocate one spare byte to guard
against a NULL return from malloc(0) being taken for an error, but
this should not be relied upon.
=========================
==> Release 0.9.7beta <==
=========================
Changes to the language proper
------------------------------
User-defined classes can now implement operations invoked through
special syntax, such as x[i] or `x` by defining methods named
__getitem__(self, i) or __repr__(self), etc.
Changes to the build process
----------------------------
Instead of extensive manual editing of the Makefile to select
compile-time options, you can now run a Configure.py script.
The Makefile as distributed builds a minimal interpreter sufficient to
run Configure.py. See also misc/BUILD
The Makefile now includes more "utility" targets, e.g. install and
tags/TAGS
Using the provided strtod.c and strtol.c are now separate options, as
on the Sun the provided strtod.c dumps core :-(
The regex module is now an option chosen by the Makefile, since some
(old) C compilers choke on regexpr.c
Changes affecting portability
-----------------------------
You need STDWIN version 0.9.7 (released 30 June 1992) for the stdwin
interface
Dynamic loading is now supported for Sun (and other non-COFF systems)
throug dld-3.2.3, as well as for SGI (a new version of Jack Jansen's
DL is out, 1.4)
The system-dependent code for the use of the select() system call is
moved to one file: myselect.h
Thanks to Jaap Vermeulen, the code should now port cleanly to the
SEQUENT
Changes to the interpreter interface
------------------------------------
The interpretation of $PYTHONPATH in the environment is different: it
is inserted in front of the default path instead of overriding it
Changes to existing built-in functions and methods
--------------------------------------------------
List objects now support an optional argument to their sort() method,
which is a comparison function similar to qsort(3) in C
File objects now have a method fileno(), used by the new select module
(see below)
New built-in function
---------------------
coerce(x, y): take two numbers and return a tuple containing them
both converted to a common type
Changes to built-in modules
---------------------------
sys: fixed core dumps in settrace() and setprofile()
socket: added socket methods setsockopt() and getsockopt(); and
fileno(), used by the new select module (see below)
stdwin: added fileno() == connectionnumber(), in support of new module
select (see below)
posix: added get{eg,eu,g,u}id(); waitpid() is now a separate function.
gl: added qgetfd()
fl: added several new functions, fixed several obscure bugs, adapted
to FORMS 2.1
Changes to standard modules
---------------------------
posixpath: changed implementation of ismount()
string: atoi() no longer mistakes leading zero for octal number
...
New built-in modules
--------------------
Modules marked "dynamic only" are not configured at compile time but
can be loaded dynamically. You need to turn on the DL or DLD option in
the Makefile for support dynamic loading of modules (this requires
external code).
select: interfaces to the BSD select() system call
dbm: interfaces to the (new) dbm library (dynamic only)
nis: interfaces to some NIS functions (aka yellow pages)
thread: limited form of multiple threads (sgi only)
audioop: operations useful for audio programs, e.g. u-LAW and ADPCM
coding (dynamic only)
cd: interface to Indigo SCSI CDROM player audio library (sgi only)
jpeg: read files in JPEG format (dynamic only, sgi only; needs
external code)
imgfile: read SGI image files (dynamic only, sgi only)
sunaudiodev: interface to sun's /dev/audio (dynamic only, sun only)
sv: interface to Indigo video library (sgi only)
pc: a minimal set of MS-DOS interfaces (MS-DOS only)
rotor: encryption, by Lance Ellinghouse (dynamic only)
New standard modules
--------------------
Not all these modules are documented. Read the source:
lib/<modulename>.py. Sometimes a file lib/<modulename>.doc contains
additional documentation.
imghdr: recognizes image file headers
sndhdr: recognizes sound file headers
profile: print run-time statistics of Python code
readcd, cdplayer: companion modules for built-in module cd (sgi only)
emacs: interface to Emacs using py-connect.el (see below).
SOCKET: symbolic constant definitions for socket options
SUNAUDIODEV: symbolic constant definitions for sunaudiodef (sun only)
SV: symbolic constat definitions for sv (sgi only)
CD: symbolic constat definitions for cd (sgi only)
New demos
---------
scripts/pp.py: execute Python as a filter with a Perl-like command
line interface
classes/: examples using the new class features
threads/: examples using the new thread module
sgi/cd/: examples using the new cd module
Changes to the documentation
----------------------------
The last-minute syntax changes of release 0.9.6 are now reflected
everywhere in the manuals
The reference manual has a new section (3.2) on implementing new kinds
of numbers, sequences or mappings with user classes
Classes are now treated extensively in the tutorial (chapter 9)
Slightly restructured the system-dependent chapters of the library
manual
The file misc/EXTENDING incorporates documentation for mkvalue() and
a new section on error handling
The files misc/CLASSES and misc/ERRORS are no longer necessary
The doc/Makefile now creates PostScript files automatically
Miscellaneous changes
---------------------
Incorporated Tim Peters' changes to python-mode.el, it's now version
1.06
A python/Emacs bridge (provided by Terrence M. Brannon) lets a Python
program running in an Emacs buffer execute Emacs lisp code. The
necessary Python code is in lib/emacs.py. The Emacs code is
misc/py-connect.el (it needs some external Emacs lisp code)
Changes to the source code that affect C extension writers
----------------------------------------------------------
New service function mkvalue() to construct a Python object from C
values according to a "format" string a la getargs()
Most functions from pythonmain.c moved to new pythonrun.c which is
in libpython.a. This should make embedded versions of Python easier
ceval.h is split in eval.h (which needs compile.h and only declares
eval_code) and ceval.h (which doesn't need compile.hand declares the
rest)
ceval.h defines macros BGN_SAVE / END_SAVE for use with threads (to
improve the parallellism of multi-threaded programs by letting other
Python code run when a blocking system call or something similar is
made)
In structmember.[ch], new member types BYTE, CHAR and unsigned
variants have been added
New file xxmodule.c is a template for new extension modules.
==================================
==> Release 0.9.6 (6 Apr 1992) <==
==================================
Misc news in 0.9.6:
- Restructured the misc subdirectory
- Reference manual completed, library manual much extended (with indexes!)
- the GNU Readline library is now distributed standard with Python
- the script "../demo/scripts/classfix.py" fixes Python modules using old
class syntax
- Emacs python-mode.el (was python.el) vastly improved (thanks, Tim!)
- Because of the GNU copyleft business I am not using the GNU regular
expression implementation but a free re-implementation by Tatu Ylonen
that recently appeared in comp.sources.misc (Bravo, Tatu!)
New features in 0.9.6:
- stricter try stmt syntax: cannot mix except and finally clauses on 1 try
- New module 'os' supplants modules 'mac' and 'posix' for most cases;
module 'path' is replaced by 'os.path'
- os.path.split() return value differs from that of old path.split()
- sys.exc_type, sys.exc_value, sys.exc_traceback are set to the exception
currently being handled
- sys.last_type, sys.last_value, sys.last_traceback remember last unhandled
exception
- New function string.expandtabs() expands tabs in a string
- Added times() interface to posix (user & sys time of process & children)
- Added uname() interface to posix (returns OS type, hostname, etc.)
- New built-in function execfile() is like exec() but from a file
- Functions exec() and eval() are less picky about whitespace/newlines
- New built-in functions getattr() and setattr() access arbitrary attributes
- More generic argument handling in built-in functions (see "./EXTENDING")
- Dynamic loading of modules written in C or C++ (see "./DYNLOAD")
- Division and modulo for long and plain integers with negative operands
have changed; a/b is now floor(float(a)/float(b)) and a%b is defined
as a-(a/b)*b. So now the outcome of divmod(a,b) is the same as
(a/b, a%b) for integers. For floats, % is also changed, but of course
/ is unchanged, and divmod(x,y) does not yield (x/y, x%y)...
- A function with explicit variable-length argument list can be declared
like this: def f(*args): ...; or even like this: def f(a, b, *rest): ...
- Code tracing and profiling features have been added, and two source
code debuggers are provided in the library (pdb.py, tty-oriented,
and wdb, window-oriented); you can now step through Python programs!
See sys.settrace() and sys.setprofile(), and "../lib/pdb.doc"
- '==' is now the only equality operator; "../demo/scripts/eqfix.py" is
a script that fixes old Python modules
- Plain integer right shift now uses sign extension
- Long integer shift/mask operations now simulate 2's complement
to give more useful results for negative operands
- Changed/added range checks for long/plain integer shifts
- Options found after "-c command" are now passed to the command in sys.argv
(note subtle incompatiblity with "python -c command -- -options"!)
- Module stdwin is better protected against touching objects after they've
been closed; menus can now also be closed explicitly
- Stdwin now uses its own exception (stdwin.error)
New features in 0.9.5 (released as Macintosh application only, 2 Jan 1992):
- dictionary objects can now be compared properly; e.g., {}=={} is true
- new exception SystemExit causes termination if not caught;
it is raised by sys.exit() so that 'finally' clauses can clean up,
and it may even be caught. It does work interactively!
- new module "regex" implements GNU Emacs style regular expressions;
module "regexp" is rewritten in Python for backward compatibility
- formal parameter lists may contain trailing commas
Bugs fixed in 0.9.6:
- assigning to or deleting a list item with a negative index dumped core
- divmod(-10L,5L) returned (-3L, 5L) instead of (-2L, 0L)
Bugs fixed in 0.9.5:
- masking operations involving negative long integers gave wrong results
===================================
==> Release 0.9.4 (24 Dec 1991) <==
===================================
- new function argument handling (see below)
- built-in apply(func, args) means func(args[0], args[1], ...)
- new, more refined exceptions
- new exception string values (NameError = 'NameError' etc.)
- better checking for math exceptions
- for sequences (string/tuple/list), x[-i] is now equivalent to x[len(x)-i]
- fixed list assignment bug: "a[1:1] = a" now works correctly
- new class syntax, without extraneous parentheses
- new 'global' statement to assign global variables from within a function
New class syntax
----------------
You can now declare a base class as follows:
class B: # Was: class B():
def some_method(self): ...
...
and a derived class thusly:
class D(B): # Was: class D() = B():
def another_method(self, arg): ...
Multiple inheritance looks like this:
class M(B, D): # Was: class M() = B(), D():
def this_or_that_method(self, arg): ...
The old syntax is still accepted by Python 0.9.4, but will disappear
in Python 1.0 (to be posted to comp.sources).
New 'global' statement
----------------------
Every now and then you have a global variable in a module that you
want to change from within a function in that module -- say, a count
of calls to a function, or an option flag, etc. Until now this was
not directly possible. While several kludges are known that
circumvent the problem, and often the need for a global variable can
be avoided by rewriting the module as a class, this does not always
lead to clearer code.
The 'global' statement solves this dilemma. Its occurrence in a
function body means that, for the duration of that function, the
names listed there refer to global variables. For instance:
total = 0.0
count = 0
def add_to_total(amount):
global total, count
total = total + amount
count = count + 1
'global' must be repeated in each function where it is needed. The
names listed in a 'global' statement must not be used in the function
before the statement is reached.
Remember that you don't need to use 'global' if you only want to *use*
a global variable in a function; nor do you need ot for assignments to
parts of global variables (e.g., list or dictionary items or
attributes of class instances). This has not changed; in fact
assignment to part of a global variable was the standard workaround.
New exceptions
--------------
Several new exceptions have been defined, to distinguish more clearly
between different types of errors.
name meaning was
AttributeError reference to non-existing attribute NameError
IOError unexpected I/O error RuntimeError
ImportError import of non-existing module or name NameError
IndexError invalid string, tuple or list index RuntimeError
KeyError key not in dictionary RuntimeError
OverflowError numeric overflow RuntimeError
SyntaxError invalid syntax RuntimeError
ValueError invalid argument value RuntimeError
ZeroDivisionError division by zero RuntimeError
The string value of each exception is now its name -- this makes it
easier to experimentally find out which operations raise which
exceptions; e.g.:
>>> KeyboardInterrupt
'KeyboardInterrupt'
>>>
New argument passing semantics
------------------------------
Off-line discussions with Steve Majewski and Daniel LaLiberte have
convinced me that Python's parameter mechanism could be changed in a
way that made both of them happy (I hope), kept me happy, fixed a
number of outstanding problems, and, given some backward compatibility
provisions, would only break a very small amount of existing code --
probably all mine anyway. In fact I suspect that most Python users
will hardly notice the difference. And yet it has cost me at least
one sleepless night to decide to make the change...
Philosophically, the change is quite radical (to me, anyway): a
function is no longer called with either zero or one argument, which
is a tuple if there appear to be more arguments. Every function now
has an argument list containing 0, 1 or more arguments. This list is
always implemented as a tuple, and it is a (run-time) error if a
function is called with a different number of arguments than expected.
What's the difference? you may ask. The answer is, very little unless
you want to write variadic functions -- functions that may be called
with a variable number of arguments. Formerly, you could write a
function that accepted one or more arguments with little trouble, but
writing a function that could be called with either 0 or 1 argument
(or more) was next to impossible. This is now a piece of cake: you
can simply declare an argument that receives the entire argument
tuple, and check its length -- it will be of size 0 if there are no
arguments.
Another anomaly of the old system was the way multi-argument methods
(in classes) had to be declared, e.g.:
class Point():
def init(self, (x, y, color)): ...
def setcolor(self, color): ...
dev moveto(self, (x, y)): ...
def draw(self): ...
Using the new scheme there is no need to enclose the method arguments
in an extra set of parentheses, so the above class could become:
class Point:
def init(self, x, y, color): ...
def setcolor(self, color): ...
dev moveto(self, x, y): ...
def draw(self): ...
That is, the equivalence rule between methods and functions has
changed so that now p.moveto(x,y) is equivalent to Point.moveto(p,x,y)
while formerly it was equivalent to Point.moveto(p,(x,y)).
A special backward compatibility rule makes that the old version also
still works: whenever a function with exactly two arguments (at the top
level) is called with more than two arguments, the second and further
arguments are packed into a tuple and passed as the second argument.
This rule is invoked independently of whether the function is actually a
method, so there is a slight chance that some erroneous calls of
functions expecting two arguments with more than that number of
arguments go undetected at first -- when the function tries to use the
second argument it may find it is a tuple instead of what was expected.
Note that this rule will be removed from future versions of the
language; it is a backward compatibility provision *only*.
Two other rules and a new built-in function handle conversion between
tuples and argument lists:
Rule (a): when a function with more than one argument is called with a
single argument that is a tuple of the right size, the tuple's items
are used as arguments.
Rule (b): when a function with exactly one argument receives no
arguments or more than one, that one argument will receive a tuple
containing the arguments (the tuple will be empty if there were no
arguments).
A new built-in function, apply(), was added to support functions that
need to call other functions with a constructed argument list. The call
apply(function, tuple)
is equivalent to
function(tuple[0], tuple[1], ..., tuple[len(tuple)-1])
While no new argument syntax was added in this phase, it would now be
quite sensible to add explicit syntax to Python for default argument
values (as in C++ or Modula-3), or a "rest" argument to receive the
remaining arguments of a variable-length argument list.
========================================================
==> Release 0.9.3 (never made available outside CWI) <==
========================================================
- string sys.version shows current version (also printed on interactive entry)
- more detailed exceptions, e.g., IOError, ZeroDivisionError, etc.
- 'global' statement to declare module-global variables assigned in functions.
- new class declaration syntax: class C(Base1, Base2, ...): suite
(the old syntax is still accepted -- be sure to convert your classes now!)
- C shifting and masking operators: << >> ~ & ^ | (for ints and longs).
- C comparison operators: == != (the old = and <> remain valid).
- floating point numbers may now start with a period (e.g., .14).
- definition of integer division tightened (always truncates towards zero).
- new builtins hex(x), oct(x) return hex/octal string from (long) integer.
- new list method l.count(x) returns the number of occurrences of x in l.
- new SGI module: al (Indigo and 4D/35 audio library).
- the FORMS interface (modules fl and FL) now uses FORMS 2.0
- module gl: added lrect{read,write}, rectzoom and pixmode;
added (non-GL) functions (un)packrect.
- new socket method: s.allowbroadcast(flag).
- many objects support __dict__, __methods__ or __members__.
- dir() lists anything that has __dict__.
- class attributes are no longer read-only.
- classes support __bases__, instances support __class__ (and __dict__).
- divmod() now also works for floats.
- fixed obscure bug in eval('1 ').
===================================
==> Release 0.9.2 (Autumn 1991) <==
===================================
Highlights
----------
- tutorial now (almost) complete; library reference reorganized
- new syntax: continue statement; semicolons; dictionary constructors;
restrictions on blank lines in source files removed
- dramatically improved module load time through precompiled modules
- arbitrary precision integers: compute 2 to the power 1000 and more...
- arithmetic operators now accept mixed type operands, e.g., 3.14/4
- more operations on list: remove, index, reverse; repetition
- improved/new file operations: readlines, seek, tell, flush, ...
- process management added to the posix module: fork/exec/wait/kill etc.
- BSD socket operations (with example servers and clients!)
- many new STDWIN features (color, fonts, polygons, ...)
- new SGI modules: font manager and FORMS library interface
Extended list of changes in 0.9.2
---------------------------------
Here is a summary of the most important user-visible changes in 0.9.2,
in somewhat arbitrary order. Changes in later versions are listed in
the "highlights" section above.
1. Changes to the interpreter proper
- Simple statements can now be separated by semicolons.
If you write "if t: s1; s2", both s1 and s2 are executed
conditionally.
- The 'continue' statement was added, with semantics as in C.
- Dictionary displays are now allowed on input: {key: value, ...}.
- Blank lines and lines bearing only a comment no longer need to
be indented properly. (A completely empty line still ends a multi-
line statement interactively.)
- Mixed arithmetic is supported, 1 compares equal to 1.0, etc.
- Option "-c command" to execute statements from the command line
- Compiled versions of modules are cached in ".pyc" files, giving a
dramatic improvement of start-up time
- Other, smaller speed improvements, e.g., extracting characters from
strings, looking up single-character keys, and looking up global
variables
- Interrupting a print operation raises KeyboardInterrupt instead of
only cancelling the print operation
- Fixed various portability problems (it now passes gcc with only
warnings -- more Standard C compatibility will be provided in later
versions)
- Source is prepared for porting to MS-DOS
- Numeric constants are now checked for overflow (this requires
standard-conforming strtol() and strtod() functions; a correct
strtol() implementation is provided, but the strtod() provided
relies on atof() for everything, including error checking
2. Changes to the built-in types, functions and modules
- New module socket: interface to BSD socket primitives
- New modules pwd and grp: access the UNIX password and group databases
- (SGI only:) New module "fm" interfaces to the SGI IRIX Font Manager
- (SGI only:) New module "fl" interfaces to Mark Overmars' FORMS library
- New numeric type: long integer, for unlimited precision
- integer constants suffixed with 'L' or 'l' are long integers
- new built-in function long(x) converts int or float to long
- int() and float() now also convert from long integers
- New built-in function:
- pow(x, y) returns x to the power y
- New operation and methods for lists:
- l*n returns a new list consisting of n concatenated copies of l
- l.remove(x) removes the first occurrence of the value x from l
- l.index(x) returns the index of the first occurrence of x in l
- l.reverse() reverses l in place
- New operation for tuples:
- t*n returns a tuple consisting of n concatenated copies of t
- Improved file handling:
- f.readline() no longer restricts the line length, is faster,
and isn't confused by null bytes; same for raw_input()
- f.read() without arguments reads the entire (rest of the) file
- mixing of print and sys.stdout.write() has different effect
- New methods for files:
- f.readlines() returns a list containing the lines of the file,
as read with f.readline()
- f.flush(), f.tell(), f.seek() call their stdio counterparts
- f.isatty() tests for "tty-ness"
- New posix functions:
- _exit(), exec(), fork(), getpid(), getppid(), kill(), wait()
- popen() returns a file object connected to a pipe
- utime() replaces utimes() (the latter is not a POSIX name)
- New stdwin features, including:
- font handling
- color drawing
- scroll bars made optional
- polygons
- filled and xor shapes
- text editing objects now have a 'settext' method
3. Changes to the standard library
- Name change: the functions path.cat and macpath.cat are now called
path.join and macpath.join
- Added new modules: formatter, mutex, persist, sched, mainloop
- Added some modules and functionality to the "widget set" (which is
still under development, so please bear with me):
DirList, FormSplit, TextEdit, WindowSched
- Fixed module testall to work non-interactively
- Module string:
- added functions join() and joinfields()
- fixed center() to work correct and make it "transitive"
- Obsolete modules were removed: util, minmax
- Some modules were moved to the demo directory
4. Changes to the demonstration programs
- Added new useful scipts: byteyears, eptags, fact, from, lfact,
objgraph, pdeps, pi, primes, ptags, which
- Added a bunch of socket demos
- Doubled the speed of ptags
- Added new stdwin demos: microedit, miniedit
- Added a windowing interface to the Python interpreter: python (most
useful on the Mac)
- Added a browser for Emacs info files: demo/stdwin/ibrowse
(yes, I plan to put all STDWIN and Python documentation in texinfo
form in the future)
5. Other changes to the distribution
- An Emacs Lisp file "python.el" is provided to facilitate editing
Python programs in GNU Emacs (slightly improved since posted to
gnu.emacs.sources)
- Some info on writing an extension in C is provided
- Some info on building Python on non-UNIX platforms is provided
=====================================
==> Release 0.9.1 (February 1991) <==
=====================================
- Micro changes only
- Added file "patchlevel.h"
=====================================
==> Release 0.9.0 (February 1991) <==
=====================================
Original posting to alt.sources.