08.1 property 装饰器

# -*- coding: utf-8 -*-
# @Time : 2021/8/1 17:47
# @Author : zy7y
# @Gitee : https://gitee.com/zy7y
# @File : property_01.py
# @Project : PythonBooks
from datetime import date, datetime
from dis import dis


class User:

    def __init__(self, name, *, birthday):
        """ * 后面的 参数 birthday 必须已关键字参数形式传递"""
        self.name = name
        self.birthday = birthday
        self._age = 0 #  代码规范，表示不想对外暴露
        self.__demo = None #  私有属性,Python内部会把其转换为 类名__demo 形式

    def get_age(self):
        return datetime.now().year - self.birthday.year

    @property
    def age(self):
        """ get
        @property： 计算属性 调用时 只需要 对象.age即可
        :return:
        """
        return datetime.now().year - self.birthday.year

    @age.setter
    def age(self, value):
        """set

        :param value:
        :return:
        """
        self._age = value


if __name__ == '__main__':
    user = User("zy7y", birthday=date(1987,1,1))
    print(user.age)
    # print(user.__demo)  #  访问私有属性 AttributeError: 'User' object has no attribute '__demo'
    print(user._User__demo)
    print(dis(User))    #  dis 可打印对象的字节码