封装的意义

#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()