added file-filter python script and README

contrib/python/.gitignore

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+*.pyc

contrib/python/README.md

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+# Python tools
+
+These python scripts are intended to manipulate measurements recorded by S2SS's `file` node-type.
+
+## Exampples
+
+##### Merge two files and filter the output based on timestamps
+
+```
+./file-merge.py testfile.dat testfile2.dat | ./file-filter.py 3 5 > output.dat
+```

contrib/python/file-filter.py

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+#!/usr/bin/env python
+
+import sys
+
+import s2ss
+from s2ss import *
+
+def main():
+	if len(sys.argv) != 3:
+		print "Usage: %s from to" % (sys.argv[0])
+		sys.exit(-1)
+
+	start = s2ss.Timestamp.parse(sys.argv[1])
+	end = s2ss.Timestamp.parse(sys.argv[2])
+
+	for line in sys.stdin:
+		msg = s2ss.Message.parse(line)
+
+		if start <= msg.ts <= end:
+			print msg
+
+if __name__ == "__main__":
+	main()