Fix definition of release_version (global).
diff --git a/Doc/tools/partparse.py b/Doc/tools/partparse.py
index bf3c78d..57ba6ef 100644
--- a/Doc/tools/partparse.py
+++ b/Doc/tools/partparse.py
@@ -29,7 +29,7 @@
 
 from types import IntType, ListType, StringType, TupleType
 
-release_version = sys.version[:3]
+release_version = string.split(sys.version)[0]
 
 # Different parse modes for phase 1
 MODE_REGULAR = 0