问题
What is the appropriate type hint to specify that a variable should be a function (the equivalent of a delegate, Func<T> or Action in C#)?
Is it also possible to specify the function argument types in a generic fashion as well (for example Func<int, int>)?
I cannot find any relevant details in the documentation.
回答1:
According to the docs, you can use Callable, imported from typing.
You can view more details in PEP 0484.
来源：https://stackoverflow.com/questions/35315824/in-python-3-5-how-can-i-specify-a-function-as-a-type-hint