sessions.py 文件源码

def __call__(self, environ, start_response):
        cookie = parse_cookie(environ.get('HTTP_COOKIE', ''))
        sid = cookie.get(self.cookie_name, None)
        if sid is None:
            session = self.store.new()
        else:
            session = self.store.get(sid)
        environ[self.environ_key] = session

        def injecting_start_response(status, headers, exc_info=None):
            if session.should_save:
                self.store.save(session)
                headers.append(('Set-Cookie', dump_cookie(self.cookie_name,
                                                          session.sid, self.cookie_age,
                                                          self.cookie_expires, self.cookie_path,
                                                          self.cookie_domain, self.cookie_secure,
                                                          self.cookie_httponly)))
            return start_response(status, headers, exc_info)
        return ClosingIterator(self.app(environ, injecting_start_response),
                               lambda: self.store.save_if_modified(session))