property与setter：属性管理

class people():
    def __init__(self,name):
        self.__name=name

    @property
    def name(self):
        return self.__name

    @name.setter
    def name(self,name):
        if not isinstance(name,str):
            raise TypeError('expected a string')
        self.__name=name

me=people("john")
print(me.name)
me.name="tony"
print(me.name)

john
tony