将多个函数应用于函数式Python中的相同参数 [英] Apply multiple functions to the same argument in functional Python

问题描述

在尝试将多个函数应用于同一个参数的情况下，我试图反转" map(相同的函数，多个参数).我正在尝试找到一种功能更强的方法来替代经典

I am trying to "invert" map (same function, multiple arguments) in a case where I have multiple function that I want to apply to the same argument. I am trying to find a more function approach to replace the classical

arg = "My fixed argument"
list_of_functions = [f, g, h] #note that they all have the same signature
[fun(arg) for fun in list_of_functions]

我唯一能想到的是

map(lambda x: x(arg), list_of_functions)

这不是很好.

推荐答案

您可以尝试:

from operator import methodcaller

map(methodcaller('__call__', arg), list_of_functions)

operator 模块还具有类似的功能，可用于获取固定属性或对象中的项，通常在功能式编程风格中很有用.不能直接调用可调用对象，但是 methodcaller 关闭足够.

The operator module also has similar functions for getting fixed attributes or items out of an object, often useful in functional-esque programming style. Nothing directly for calling a callable, but methodcaller is close enough.

不过，在这种情况下，我个人更喜欢列表理解.也许operator模块中有直接等效项，例如:

Though, I personally like list comprehension more in this case. Maybe if there was a direct equivalent in the operator module, like:

def functioncaller(*args, **kwargs):
    return lambda fun:fun(*args, **kwargs)

...将其用作:

map(functioncaller(arg), list_of_functions)

...那也许足够方便吗?

…then maybe it would be convenient enough?

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