The list description should make clear why any of the existing lists was deemed a good fit:
Development of Python bindings
* it's for the implementation details and you need to know C, not Python
* questions about the internals are on-topic, even if you're not developing the internals themselves
* it's a single place to discuss pygtk, pygi, pygobject wrapper implementations
So if you are worried about how your GNOME apps written in Python are going to transition to GNOME 3.x and Python 3.x, join us before it's too late!