Armin Rigo's cProfile is pretty cool, and will be in Python 2.5. KCacheGrind is basically the most awesome profile analysis tool I have ever seen. But how can you use cProfile with KCacheGrind? Itamar and I took a patch against lsprof (cProfile's immediate ancestor) from David Allouche's blog, changed it to be a stand-alone module and updated it to work with cProfile. It's pretty awesome. If you are profiling Python you almost certainly cannot live without it.