The uu.py library for uuencoding and uudecoding does not support base64 encodins. The patch addached here adds base64 decoding, but does not add encoding support.
I think the 2.4 version is in maintenance mode, so no new features are added. You may target 2.5 or 2.6. But the patch is incorrect: the base64 name is undefined. You should include test cases and documentation changes also; please read http://www.python.org/dev/patches/