Python is better at doing analysis or perhaps I should say 'machine learning' 'on the fly'. For example it may be better at following nodes (or leads) through a twitter feed. Python might be able to learn how to find the best pages.

However, I doubt this is a feature of the Python language itself. It's more likely the libraries that you can load into Python that provide this functionality. Many libraries have APIs for multiple languages, so it'd probably be possible to use the exact same, or at least similar, libraries from Perl instead of Python, and then IMHO the advantages shift towards using only one programming language.