Python中如何指定dictionary的key值类型

Python 笔记

一、背景介绍

二、使用类作为dictionary的key值

class Key:
    def __init__(self, value):
        self.value = value

    def __eq__(self, other):
        if isinstance(other, Key):
            return self.value == other.value
        return False

    def __hash__(self):
        return hash((type(self), self.value))

my_dict = {Key('key'): 'value'}
print(my_dict[Key('key')])

三、使用typing.Dict指定key值类型

from typing import Dict

my_dict: Dict[str, int] = {'one': 1, 'two': 2}
print(my_dict['one'])

四、通过类型提示实现key值类型检查

def my_dict_func(my_dict: dict[str, int]) -> int:
    return my_dict['one']

print(my_dict_func({'one': 1, 'two': 2}))

五、结论