Typed Undefined

当 None 不是有效的默认值时，您始终可以使用 undefined。

from undefined import Undefined, undefined, resolve


def foo(bar: Undefined[int] = undefined) -> int:
    return resolve(undefined, 10)


foo(1)  # ok
foo(1.0)  # error

a: Undefined[int] = 1  # ok
b: Undefined[int] = 0.5  # error

mypy集成

您应将 undefined_mypy 添加到mypy插件的列表中

[mypy]
plugins = undefined.mypy