python利用字典实现全局变量

1、创建一个字典用于保存变量
# dict
import collections


class GlobalDict(collections.UserDict):
    """使用继承UserDict"""

    def __missing__(self, key):
        """获取不存在的值时"""
        return None


my_dict = GlobalDict()

2、引用my_dict 保存全局变量

# global_dict
from dict import my_dict


my_dict['key1'] = 1
my_dict['key2'] = 2

3、使用my_dict作为全局变量的字典

from global_dict import my_dict

print(my_dict)