MyPy isn't quite as nice as typescript, and it also has some trouble with Django. I know it CAN work, but does any language have a worse type system? Maybe Ruby.
For single line conditionals - looks like you're right from that I can tell. I mistakenly assumed the pep8 errors were actually interpreter errors. Thank you!
I believe that the reason you're having issues with Django is that Django lacks types on its external interfaces. This isn't an issue with MyPy. You're conflating language-level issues with code-level issues. Python's type hints are quite powerful, assuming you're using stuff that provides them. At this point, it has a better type system than Go (if only because it has sum types and option types), but it's opt-in.
For single line conditionals - looks like you're right from that I can tell. I mistakenly assumed the pep8 errors were actually interpreter errors. Thank you!