[throwawayffffas]

I have the sneaking suspicion that for the vast majority of code it could be done.

I don't think the operator overloading is such a big issue since you can do the same kind of tracing for the overloaded operator.

The main issues would be metaclasses and all sort of monkey patching etc. i.e. anything that could mutate a type at runtime because the linter can't know if the mutation has happened.

Unfortunately I do not have the time nor patience to introduce the sixth type checker.

[HelloNurse]

You need to distinguish the prevention of actual type errors during the execution of a Python program, which would require mutilating the Python language, and linting Python code to find proven or likely defects, which is merely fraught with complications (open world and closed world assumptions, expecting more or less adversarial behaviour from callers of a function, etc.) and necessarily dependent on adding optional type declarations.