I hope nobody minds me being a bit crassly commercial on this list, but I wanted to announce that Robert Smallshire and I have just published the first three chapters of our new introductory Python book, "The Python Apprentice":
https://leanpub.com/python-apprentice/
It's based on our popular PluralSight courses, so if you are someone you know wants to learn Python, it's a great place to start. More chapters should be coming out soon.
Austin