change torrent tracker tool

change-tracker.py

+#! /usr/bin/env python
+import sys
+import bencode
+
+torrentIn = sys.argv[1]
+tracker = sys.argv[2]
+torrentOut = sys.argv[3]
+
+with open(torrentIn, 'rb') as f:
+    bencoded = f.read()
+
+data = bencode.bdecode(bencoded)
+data['announce'] = tracker
+bencoded = bencode.bencode(data)
+
+with open(torrentOut, 'wb') as f:
+    f.write(bencoded)