方法一，通过枚举类型实现

• 缺点可以动态添加新属性
  -代码实现

from enum import Enum

class Constants(Enum):
    AGE:int = 18
    NAME:str = "TOM"

# Constants.AGE = 20 # AttributeError: cannot reassign member 'AGE'
# Constants.WEIGHT =  100 # can add new attributeerror

方法二通过__setattr__ 和Type

• 代码实现

from typing import Union


class MetaConstant(type):

    ALLOWED_ATTR = {

    }

    def __setattr__(cls, name:str, value:Union[str, int, float]):
        name = name.upper()
        if name not in cls.ALLOWED_ATTR:
            raise AttributeError(f"Cannot set class attribute '{name}' on class '{cls.__name__}'")
        elif hasattr(cls, name):
            raise AttributeError(f"Cannot modify Constants attribute {name}")
        super().__setattr__(name, value)


class Constants(metaclass=MetaConstant):
    ALLOWED_ATTR = {
        "AGE",
        "NAME"
    }

    AGE:int = 18
    NAME:str = 'TOM'


print(Constants.AGE)
# Constants.AGE = 20 # AttributeError: Cannot modify Constants attribute AGE
# Constants.weight = 100 # AttributeError: Cannot set class attribute 'WEIGHT' on class 'Constants'