[IDEA] Look into MyPy and Django-Stubs for strict type checking

[TreyWW]

I recently came across django-stubs and mypy and they look really interesting. It could add a good type neatness to the project to allow easier future readability and also in general help know what things are.
I've been implementing invoice schedules and used a lot of functions for re-usability and here I'm realising a stricter type checker would be really ideal.

I'd like to hear opinions on this, drop a comment! :)