Python: 打印的打字签名是什么？

Question

当定义为 Callable 参数时，print 或类似函数的类型签名是什么，它采用可变数量的任何类型的参数？

具体来说，这里output_function的声明是什么？

def f(x: str, output_function=print):
    output_function(x)

更新：澄清为可调用参数。

Answer 1

来自PEP 484

Arbitrary argument lists can as well be type annotated, so that the definition:
def foo(*args: str, **kwds: int): ...
is acceptable and it means that, e.g., all of the following represent function calls with valid types of arguments:
foo('a', 'b', 'c')
foo(x=1, y=2)
foo('', z=0)

所以 print 将是：

from typing import Any, IO
def print(*args: Any, sep: str = ' ', \
          end: str = '\n', file: IO = sys.stdout, \
          flush: bool = False) -> None:

不过我认为您不能将此应用于 Callable。来自 docs for typing,

There is no syntax to indicate optional or keyword arguments; such function types are rarely used as callback types. Callable[..., ReturnType] (literal ellipsis) can be used to type hint a callable taking any number of arguments and returning ReturnType

Python: 打印的打字签名是什么？

Python: What is the typing signature for print?

python

typing