封装到底是用来干些什么事?封装的意义
封装数据属性:
来明确的区分内外,控制外部对隐藏的属性的操作行为
class People:
def __init__(self, name, age):
self.__name = name
self.__age = age
def tell_info(self):
print('Name:<%s> Age:<%s>' % (self.__name, self.__age))
def set_info(self, name, age):
if not isinstance(name, str):
print('名字必须是字符串类型')
if not isinstance(age, int):
print('年龄必须是数字类型')
self.__name = name
self.__age = age
p = People('wyq', 18)
p.tell_info()
封装方法:
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('输入取款金额')
def __print_bill(self):
print('打印账单')
def __take_money(self):
print('取款')
def withdraw(self):
self.__card()
self.__auth()
self.__input()
self.__print_bill()
self.__take_money()
a = ATM()
a.withdraw()