08.5 metaclass

# -*- coding: utf-8 -*-
# @Time : 2021/8/1 18:48
# @Author : zy7y
# @Gitee : https://gitee.com/zy7y
# @File : metaclass.py
# @Project : PythonBooks
"""
类也是对象，type是创建类的类， type 也是object 的子类
"""


# 动态创建类 type
"""
 type(object_or_name, bases, dict)
        type(object) -> the object's type
        type(name, bases, dict) -> a new type
        # (copied from class doc)
"""

def say(self):
    """该方法 需要给实例，绑定到元类上"""
    print("say.")
    return 1

# 创建 User类， () 不继承类， {} 属性 或者方法

User = type("User", (), {"name": "小明", "say": say})

class Super(type):
    def __new__(cls, *args, **kwargs):
        return super().__new__(cls, *args, **kwargs)


class User(metaclass=Super):
    """实例化过程中 寻找metaclass ，通过它去创建User类， 找不到时 就会调用type 创建类"""
    def __str__(self):
        return "User obj"

if __name__ == '__main__':
    user = User()
    # print(user.name)
    # print(user.say())
    print(user)