带有两个或多个返回参数的函数注解 [英] Function annotation with two or more return parameters

问题描述

当我为返回一个参数的函数编写注释时，我没有问题.

When I write an annotation for a function which returns one parameter, I have no problems.

def func() -> str:
    return "ok"

然而，当我写一个带有两个或更多参数的注解时，我的 PyCharm 给了我SyntaxError: invalid syntax.

However, when I write an annotation with two or more parameters, my PyCharm gives me SyntaxError: invalid syntax.

def func() -> str, str:
    return "ok - 1", "ok - 2"

我认为参数可以与 tuple 组合，但我认为这不是最好的方法.

I think that the parameters can be combined with a tuple, but I don't think that's the best way to do it.

我的问题是:如何正确注释具有两个或多个返回参数的函数?

My question is: how can I properly annotate a function with two or more return parameters?

请在您的回复中包含 PEP 链接(如果有).我在 PEP 484 和 PEP 3107 却找不到.

Please include a PEP link, if any, in your response. I looked for the answer at PEP 484 and PEP 3107 and could not find it.

推荐答案

使用 typing.Tuple:

from typing import Tuple

def func() -> Tuple[str, str]:
    return 'a', 'b'

这是合适的，因为从概念上讲，您实际上是在返回一个包含这些值的 tuple.注意:

This is appropriate because, conceptually, you are actually returning a single tuple containing those values. Note:

print(type(func()))

输出:

<class 'tuple'>

除了空的 tuple (())，括号不是定义元组所必需的，这意味着'a', 'b' 被创建为一个 tuple，而不是由 return 语句将单独的值聚集在一起.

Except for the empty tuple (()), parentheses are not necessary to define a tuple, which means that 'a', 'b' is created as a tuple, rather than being separate values gathered into one by the return statement.

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