commit -- why not...

Demo/comparisons/sortingtest.py

@@ -0,0 +1,50 @@
+#! /usr/local/bin/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 regex
+import string
+import sys
+
+def main():
+	prog = regex.compile('^\(.*\)=\([-+]?[0-9]+\)')
+	def makekey(item, prog=prog):
+		if prog.match(item) >= 0:
+			var, num = prog.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 = string.split(line)
+		items = map(makekey, items)
+		items.sort()
+		for num, var in items:
+			print "%s=%s" % (var, num),
+		print
+
+main()