python – mypy,type提示：Union [float,int] – >是否有Number类型？

mypy非常方便并且捕获了很多错误,但是当我编写“科学”应用程序时,我经常最终会这样做：

def my_func(number: Union[float, int]):
    # Do something

number是float或int,具体取决于用户的输入.有官方的方法吗？

解决方法:

仅使用float,因为int隐含在该类型中：

def my_func(number: float):

PEP 484 Type Hints明确指出：

Rather than requiring that users write import numbers and then use numbers.Float etc., this PEP proposes a straightforward shortcut that is almost as effective: when an argument is annotated as having type float, an argument of type int is acceptable; similar, for an argument annotated as having type complex, arguments of type float or int are acceptable.

(大胆强调我的).

理想情况下,你仍然会使用numbers.Real：

from numbers import Real

def my_func(number: Real):

因为它会接受fractions.Fraction()和decimal.Decimal()对象;数字金字塔不仅仅是整数和浮点值.

但是,当使用mypy进行类型检查时,这些当前不起作用,请参阅Mypy #3186.

标签：type-hinting,python,mypy
来源： https://codeday.me/bug/20190910/1800777.html