Flask中after_request的一个坑为什么

flask的after_request函数一定要返回response

即使你没有对response做任何处理

你只有一个after_request函数的时候不会出现问题，一旦一些插件用到了after_request多半就会报错，类似于None type has no attribute xxx这样。

为什么

flask处理after_request是在下面这个方法里面，在app.py

    def process_response(self, response):
        """Can be overridden in order to modify the response object
        before it's sent to the WSGI server.  By default this will
        call all the :meth:`after_request` decorated functions.

        .. versionchanged:: 0.5
           As of Flask 0.5 the functions registered for after request
           execution are called in reverse order of registration.

        :param response: a :attr:`response_class` object.
        :return: a new response object or the sam