封装的意义

Posted 2021-02-02 yuexijun

#封装的意义：明确的区分内外，控制外部对隐藏属性的操作
class People:
    def __init__(self, name, age):
        self.__name = name
        self.__age = age
        #print(‘名字是%s年纪是%s‘%self.__name,self.__age)
    def tell_info(self, name, age):
        self.__name = name
        self.__age = age
        print(‘名字是%s年纪是%s‘ %(self.__name, self.__age))
    def set_info(self, name, age):
        if not isinstance(name, str):
            print(‘必须是字符串‘)
            return
        if not isinstance(age, int):
            print(‘必须是数字‘)
            return
        self.__name = name
        self.__age = age
        print(‘名字是%s年纪是%s‘ % (self.__name, self.__age))
p = People(‘laowang‘, 23)
#p.tell_info(‘huanggua‘, 25)
p.set_info(‘wangba‘, 58)
print(p.__dict__)
#封装方法的目的 ：隔离复杂度
class ATM:
    def __card(self):
        print(‘插卡‘)
    def __auth(self):
        print(‘用户认证‘)
    def __input(self):
        print(‘输入金额‘)
    def __print_bill(self):
        print(‘打印账单‘)
    def __take_money(self):
        print(‘取款成功‘)
    def withdrw(self):
        self.__card()
        self.__auth()
        self.__input()
        self.__print_bill()
        self.__take_money()
a = ATM()
a.withdrw()