如何将关键字参数作为参数传递给函数? [英] How can I pass keyword arguments as parameters to a function?

问题描述

假设我有一个这样定义的函数:

Say I have a function defined thus:

def inner_func(spam, eggs):
    # code

然后我想调用这样的函数:

I then want to call a function like this:

outer_func(spam=45, eggs="blah")

Inside outer_func 我希望能够使用传递给 outer_func 的完全相同的参数调用 inner_func.

Inside outer_func I want to be able to call inner_func with exactly the same parameters that were passed into outer_func.

这可以通过像这样编写 outer_func 来实现:

This can be achieved by writing outer_func like this:

def outer_func(spam, eggs):
    inner_func(spam, eggs)

但是，我希望能够更改 inner_func 接受的参数，并相应地更改我传递给 outer_func 的参数，但无需更改outer_func 每次.

However, I'd like to be able to change the arguments inner_func takes, and change the parameters I pass to outer_func accordingly, but without having to change anything in outer_func each time.

有没有(简单的)方法可以做到这一点?请使用 Python 3.

Is there a (easy) way to do this? Python 3 please.

推荐答案

看起来您正在寻找 * 和 ** 符号:

Looks like you're looking for the * and ** notations:

def outer_func(*args, **kwargs):
    inner_func(*args, **kwargs)

然后你可以做outer_func(1, 2, 3, a='x', b='y')，outer_func会调用inner_func(1, 2, 3, a='x', b='y').

Then you can do outer_func(1, 2, 3, a='x', b='y'), and outer_func will call inner_func(1, 2, 3, a='x', b='y').

如果您只想允许关键字参数，请删除 *args.

If you only want to allow keyword arguments, drop the *args.

在函数定义中，标有 * 的参数接收所有与其他声明参数不对应的位置参数的元组，以及标有 ** 的参数> 接收与其他声明参数不对应的所有关键字参数的字典.

In a function definition, a parameter marked with * receives a tuple of all positional arguments that didn't correspond to other declared parameters, and an argument marked with ** receives a dict of all keyword arguments that didn't correspond to other declared parameters.

在函数调用中，在序列(或其他可迭代)参数前加上 * 将其解包为单独的位置参数，并在映射参数前加上 ** 将其解包成单独的关键字参数.

In a function call, prefixing a sequence (or other iterable) argument with * unpacks it into separate positional arguments, and prefixing a mapping argument with ** unpacks it into separate keyword arguments.

这篇关于如何将关键字参数作为参数传递给函数?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！