It was more work than it should have been, but you can get access to a MySQL database from Python on OS X 10.5 by following the instructions at this blog post.

If you’re using Pydev in Eclipse, be sure /Library/Python/2.5/site-packages is in the System PYTHONPATH. Bring up the Preferences dialog, open Pydev in the tree, click on Interpreter - Python, click New Folder to the right of System PYTHONPATH, and then add the directory, if necessary.