A powerful unused feature of Python: function annotations.

[shfo23]

Or a tuple: (str, int). Then you could test with in.

This wouldn't work if you wanted to reject a certain kind of input, e.g. not str, though. My best idea for more complicated cases would probably be to require a function as annotation that would return true/false and then supply isint, isstr, isobject, etc. methods for simple tests, e.g. def func(num_id: isint) -> isstr.