源代码example.py：
from typing import Union, Any
import numpy as np
Number = Union[int, float, np.floating[Any]]
def add_one(num: Number) -> Number:
return num + 1
inputs = [1, 2, 3]
outputs = [add_one(n) for n in inputs]
avg = np.mean(outputs)
运行 mypy：
mypy example.py
src/example.py:14: error: Argument 1 to "mean" has incompatible type "List[Union[float, floating[Any]]]"; expected "Union[_SupportsArray[dtype[Any]], _NestedSequence[_SupportsArray[dtype[Any]]], bool, int, float, complex, str, bytes, _NestedSequence[Union[bool, int, float, complex, str, bytes]]]"
Found 1 error in 1 file (checked 1 source …