property装饰器

property装饰器：将一个函数功能伪装成一个数据属性
版本一：

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

      @property
      def name(self):
          return self.__name #obj.name访问的是self.__NAME(这也是真实值的存放位置)

      @name.setter
      def name(self, v):
        if type(v) is not str:
          print("必须是str类型")
          return
        self.__name = v
      @name.deleter
      def name(self):
          print("不能删除")

    obj = People('ly', 18)
    print(obj.name)
    print(obj.get_name)
    obj.set_name('EGON')
    obj.name = 'x'
    print(obj.name)
    del  obj.name

版本二：

class People():
    __country = 'CHINA'  # _People__country
    def __init__(self, name, age):
        self.__name = name
        self.age = age
    def get_name(self):
        return self.__name

    def set_name(self, v):
        if type(v) is not str:
            print("必须是str类型")
            return
        self.__name = v

    def del_name(self):
        print("不能删除")

        # 这样写， 必须按照这个顺序
    xxx = property(get_name, set_name, del_name)

obj = People('ly', 18)
print(obj.xxx)
obj.xxx = 'EGON'
print(obj.xxx)
del  obj.xxx