- # 类也是对象, type 创建类的类
- def create_class(name):
- if name == "user":
- class User:
- def __str__(self):
- return "user"
- return User
- elif name == "company":
- class Company:
- def __str__(self):
- return "company"
- return Company
- #type 动态创建类
- # User = type("User", (), {}) #名称, 继承 (要继承的 base 类), 属性或方法 (但是要字典形式)
- def say(self):
- return "i am user"
- # return self.name
- class BaseClass():
- def answer(self):
- return "i am baseclass"
- class MetaClass(type): #继承 type 为元类
- def __new__(cls, *args, **kwargs):
- return super().__new__(cls, *args, **kwargs)
- from collections.abc import *
- # 什么是元类, 元类是创建类的类 对象 <-class(对象)<-type
- class User(metaclass=MetaClass):
- def __init__(self, name):
- self.name = name
- def __str__(self):
- return "user"
- #python 中类的实例化过程, 会首先寻找 metaclass, 通过 metaclass 去创建 user 类
- #type 去创建类对象, 实例
- if __name__ == "__main__":
- # MyClass = create_class("user")
- # my_obj = MyClass()
- # print(type(my_obj))
- # User = type("User", (BaseClass, ), {"name":"user", "say":say})
- my_obj = User(name="bobby")
- print(my_obj)
来源: http://www.bubuko.com/infodetail-2567829.html