And I'm not sure about the fine-grained accuracy here. For example, NetworkX is listed green, but its graphic subsystem, according to their documentation, does not support Python 3.

Also, Oath2 seems like a big one, and would exclude many other packages that might use it.

It is all self-reporting based on the classifiers given to PyPI (NetworkX lists itself as supporting Python 3, Python3.2–Python3.4). It seems like both it and twisted would benefit from a Python3–partial classifier