ref: c881e33e8ed668f4d5a2102c113e3edb1ea80d44
dir: /sys/src/cmd/python/Demo/comparisons/sortingtest.py/
#! /usr/bin/env python
# 2) Sorting Test
#
# Sort an input file that consists of lines like this
#
# var1=23 other=14 ditto=23 fred=2
#
# such that each output line is sorted WRT to the number. Order
# of output lines does not change. Resolve collisions using the
# variable name. e.g.
#
# fred=2 other=14 ditto=23 var1=23
#
# Lines may be up to several kilobytes in length and contain
# zillions of variables.
# This implementation:
# - Reads stdin, writes stdout
# - Uses any amount of whitespace to separate fields
# - Allows signed numbers
# - Treats illegally formatted fields as field=0
# - Outputs the sorted fields with exactly one space between them
# - Handles blank input lines correctly
import re
import string
import sys
def main():
prog = re.compile('^(.*)=([-+]?[0-9]+)')
def makekey(item, prog=prog):
match = prog.match(item)
if match:
var, num = match.group(1, 2)
return string.atoi(num), var
else:
# Bad input -- pretend it's a var with value 0
return 0, item
while 1:
line = sys.stdin.readline()
if not line:
break
items = line.split()
items = map(makekey, items)
items.sort()
for num, var in items:
print "%s=%s" % (var, num),
print
main()