Demo/comparisons/sortingtest.py

   1 #! /usr/bin/env python
   2
   3 # 2)  Sorting Test
   4 #
   5 #     Sort an input file that consists of lines like this
   6 #
   7 #         var1=23 other=14 ditto=23 fred=2
   8 #
   9 #     such that each output line is sorted WRT to the number.  Order
  10 #     of output lines does not change.  Resolve collisions using the
  11 #     variable name.   e.g.
  12 #
  13 #         fred=2 other=14 ditto=23 var1=23
  14 #
  15 #     Lines may be up to several kilobytes in length and contain
  16 #     zillions of variables.
  17
  18 # This implementation:
  19 # - Reads stdin, writes stdout
  20 # - Uses any amount of whitespace to separate fields
  21 # - Allows signed numbers
  22 # - Treats illegally formatted fields as field=0
  23 # - Outputs the sorted fields with exactly one space between them
  24 # - Handles blank input lines correctly
  25
  26 import regex
  27 import string
  28 import sys
  29
  30 def main():
  31         prog = regex.compile('^\(.*\)=\([-+]?[0-9]+\)')
  32         def makekey(item, prog=prog):
  33                 if prog.match(item) >= 0:
  34                         var, num = prog.group(1, 2)
  35                         return string.atoi(num), var
  36                 else:
  37                         # Bad input -- pretend it's a var with value 0
  38                         return 0, item
  39         while 1:
  40                 line = sys.stdin.readline()
  41                 if not line:
  42                         break
  43                 items = string.split(line)
  44                 items = map(makekey, items)
  45                 items.sort()
  46                 for num, var in items:
  47                         print "%s=%s" % (var, num),
  48                 print
  49
  50 main()