great resource!! what is it about NZ and machine learning :)
(weka comes from there, for those who are not aware)
Anyway, PyML (<a href="http://pyml.sourceforge.net/" rel="nofollow">http://pyml.sourceforge.net/</a>) and biopython (<a href="http://biopython.org" rel="nofollow">http://biopython.org</a>) are two other packages I found pretty useful and can be explored..
Pretty good code, and quite a bit of it. It's hardly a "repository", though, as it's just example code from the site's book. There is, however, a nice link down at the very bottom for machine learning data sets. Gotta save that one...<p>Taking into account that it's meant to go with the book, it's even decently commented. In quite a few of them, though, it'd be hard to puzzle out reasons for doing things without already knowing the logic.