I am no Python expert, but there must be modules (easyinstall etc) for inversion of control etc in Python too, as there should be in all scripting languages. (Is it really in the std lib of Java?! Ah, maybe I'm not that surprised...)
(I am from a Perl environment which have a bit emphasis on tools/libraries and language extensions, because it is easy to do with automatical tests on most every platform/Perl version.)