What is really being used out there for greenfield development in shops that already use python? What important libraries/frameworks really aren't moving to 3.3, or have completely abandoned 2.7, so are "Reasons to pick" that version?
Is there a way to check compatibility with less known packages? I use Flask quite often and it has been Python 3 compatible for a while, but there are a lot of extensions for it which of course can't be found in such a list. Some only mention support in their changelogs, some not at all.
https://python3wos.appspot.com/