可变数量参数（`args` 或 `kwargs`）的重载类型

Question

示例如下，需要确保 IDE 类型检查器或

reveal_type

能够正确识别

k

、

j

和

i

类型。

也许有某种方法可以建议输入

args

是空

tuple

和

kwargs

空

dict

，然后返回值将是

tuple[int]

？

from typing import Union, overload

def test(*args: int, **kwargs: str) -> Union[int, str, tuple[int]]:
    if args:
        return 5
    if kwargs:
        return "5"
    return (5,)


# now all are Union[int, str, tuple[int]]
k = test(1)
j = test(i="1")
i = test()

reveal_type(k) # should be int
reveal_type(j) # should be str
reveal_type(i) # should be tuple[int]

Answer 1

这是一个部分解决方案，至少允许 mypy 推断

k

、

j

和

i

的正确类型。所需的签名基本上是重叠的，所以我不确定是否可以对过载重叠错误采取任何措施。

from typing import Union, overload


@overload
def test() -> tuple[int]:  # type: ignore[overload-overlap]
    ...
    
@overload
def test(*args: int) -> int:  # type: ignore[overload-overlap]
    ...
    
@overload
def test(**kwargs) -> str:
    ...

def test(*args: int, **kwargs: str) -> Union[int, str, tuple[int]]:
    if args:
        return 5
    if kwargs:
        return "5"
    return (5,)


# now all are Union[int, str, tuple[int]]
k = test(1)
j = test(i="1")
i = test()

reveal_type(k) # should be int
reveal_type(j) # should be str
reveal_type(i) # should be tuple[int]

mypy v1.9.0 输出（在线尝试！）：

main.py:29: note: Revealed type is "builtins.int"
main.py:30: note: Revealed type is "builtins.str"
main.py:31: note: Revealed type is "tuple[builtins.int]"
Success: no issues found in 1 source file