On Sun, May 17, 2015 at 3:07 PM, Alex Grönholm
Looking at PEP 484, I came up with two use cases that I felt were not catered for:
1. Specifying that a parameter should be a subclass of another (example: Type[dict] would match dict or OrderedDict; plain "Type" would equal "type" from builtins)
I don't understand. What is "Type"? Can you work this out in a full example? This code is already okay: def foo(a: dict): ... foo(OrderedDict())
1. Specifying that a callable should take at least the specified arguments but would not be limited to them: Callable[[str, int, ...], Any]
Case #2 works already (Callable[[str, int], Any] if the unspecified arguments are optional, but not if they're mandatory. Any thoughts?
For #2 we explicitly debated this and found that there aren't use cases known that are strong enough to need additional flexibility in the args of a callable. (How is the code calling the callable going to know what arguments are safe to pass?) If there really is a need we can address in a future revision. -- --Guido van Rossum (python.org/~guido)