xxx() missing 1 required positional argument: 'self'

求知探索 1年前 ⋅ 806 阅读

装饰实例方法的时候容易出现莫名其妙的错误,所以一般加上get方法,来个案例:

import types
from functools import wraps

class Log(object):
    def __init__(self, func):
        wraps(func)(self)  # @wraps(func) 访问不到,所以用这种方式
        self.__func = func

    def __call__(self, *args, **kvs):
        print("%s log_info..." % self.__func.__name__)
        return self.__func(*args, **kvs)

    # 装饰实例方法的时候容易出现莫名其妙的错误,所以一般加上get方法
    # eg:show() missing 1 required positional argument: 'self'
    def __get__(self, instance, cls):
        if instance is None:
            return self
        else:
            return types.MethodType(self, instance)

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

    @Log
    def show(self):
        """实例方法"""
        print("欢迎你:%s" % self.__name)

    @classmethod
    @Log  # 写在下面("从下往上装,从上往下拆")
    def login_in(cls):
        """类方法"""
        print("登录ing")

    @staticmethod
    @Log
    def show_news():
        """静态方法"""
        print("今天的新闻是...")

def main():
    LoginComponent.login_in()
    LoginComponent.show_news()
    login = LoginComponent("小明")
    login.show()

if __name__ == '__main__':
    main()

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