A few reasons: - Python3 makes some concepts, like unicode, division, the print function, etc, simpler to understand. - Almost all major packages (only scrapy

A few reasons: - Python3 makes some concepts, like unicode, division, the print function, etc, simpler to understand. - Almost all major packages (only scrapy doesn't that I can think of), including the scientific stack, are compatible with 3. - The trend towards 3 seems to be accelerating. 2 isn't going away anytime soon, but I'd like this content to be relevant for some time. Ultimately, they aren't that different, and I may have a section listing out what you need to do to switch between them.