If I am understanding correctly, everything in requirements folder is dev and extras. The requirements.txt is the base requirements to build papermill. The docs/requirements.txt should have both the docs requirements and the package requirements which doesn't currently work. Does that align with other's understanding.

I'm going to when I have time...try to switch this to the more modern packaging format. I think if we use hatch we can get rid of a bunch of stuff including tox and slim down the config files and lean more into pyproject.toml. This should improve maintainability.

Yes I think Python3.13 might force the issue anyway, but I agree we need to redo the setup.py / requirements pattern.

Would you be in favor of moving out of tox? and using pure pytest and GHA?

Maintainer of Hatch and Hatchling here! Let me know if I can be of assistance 🙂