I once had dinner with a Stanford professor, years back, who was talking about the fact that he liked teaching in Python because he spent way less time teaching the language and more the higher level stuff that he was actually trying to get across than when he was using C++. Lower barrier to entry for new users. I'd guess that probably in the intervening years, a lot of classes have decided to use it for similar reasons. If you want to teach, I dunno, signal processing and your students maybe don't have a great handle on the language yet, you want to be spending time on the signal processing stuff, not on language concepts.