mypy 可以处理列表理解吗?

Can mypy handle list comprehensions?

from typing import Tuple
def test_1(inp1: Tuple[int, int, int]) -> None:
    pass

def test_2(inp2: Tuple[int, int, int]) -> None:
    test_tuple = tuple(e for e in inp2)
    reveal_type(test_tuple)
    test_1(test_tuple)

虽然 运行 mypy 在上面的代码中,我得到:

error: Argument 1 to "test_1" has incompatible type "Tuple[int, ...]"; expected "Tuple[int, int, int]"

test_tuple不保证有3个int元素吗? mypy 是否不处理此类列表理解,或者是否有另一种定义类型的方法?

从 0.600 版开始,mypy 不会在这种情况下推断类型。正如 GitHub.

上所建议的那样,这将很难实施

相反,我们可以使用 cast(参见 mypy docs):

from typing import cast, Tuple

def test_1(inp1: Tuple[int, int, int]) -> None:
    pass

def test_2(inp2: Tuple[int, int, int]) -> None:
    test_tuple = cast(Tuple[int, int, int], tuple(e for e in inp2))
    reveal_type(test_tuple)
    test_1(test_tuple)