# -*- coding:utf-8 -*-
"""元类的使用"""
__author__ = 'Eddie Chow'


def fn(self, name='world'):
    print('Hello , %s' % name)


def add(self, value):
    self.append(value)


class MyListMetaClass(type):
    def __new__(cls, name, bases, attrs):
        print('通过元类来创建一个类：%s，%s，%s，%s' % (cls, name, bases, attrs))
        attrs['add'] = add
        return type.__new__(cls, name, bases, attrs)


class MyList(list, metaclass=MyListMetaClass):
    pass


if __name__ == '__main__':
    Hello = type('Hello', (object,), dict(hello=fn))
    h = Hello()
    h.hello()
    # class的类型就是 type
    print(type(Hello))
    # 实例的类型就是 Hello
    print(type(h))
    # 用元类创建类
    mylist = MyList()
    mylist.append(1)
    mylist.add(2)
    print(mylist)