What is the data type of a parameter that is a function?

Question

When I create a function, I often specify the data types of its arguments, for example:

def my_func(name: str, surname: str) -> str:
       full_name = name + surname
       return full_name

but if an argument of a function is another function, what is its data type?

I tried to do this:

def my_func_2(func: function) -> str: 
    return func()

but I get

NameError: name function is not defined

Answer 1

You should find something useful in module typing.

def my_func_2(func: typing.Callable) -> str: 

The cleanest solution is to import only Callable from the module, to prevent the function's prototype to be too long.

from typing import Callable

def my_func_2(func: Callable) -> str: