TypeError The view function did not return a valid response. The function either returned None 的解决

推荐整理分享TypeError The view function did not return a valid response. The function either returned None 的解决，希望有所帮助，仅作参考，欢迎阅读内容。

文章相关热门搜索词:,内容如对您有帮助，希望把文章链接给更多的朋友！

使用flask框架制作登录、注册的页面时，app.py运行成功，数据库有用户，1234，密码也是1234

点击登录之后， 报如下错误。

TypeError: The view function did not return a valid response. The function either returned None or ended without a return statement.

页面截图如下：

查网上的报错，解决办法是路由没有返回东西，于是我改了return语句，if和else都有返回值。

但是再次运行的时候还是报同样的错误。

于是我看了以下python控制台。

Traceback (most recent call last): File “D:技术学习卫生健康委员会登录页面cpe项目代码登录界面app.py”, line 65, in getLoginRequest cursor.execute(sql) File “D:pythonlibsite-packagespymysqlcursors.py”, line 163, in execute result = self._query(query) File “D:pythonlibsite-packagespymysqlcursors.py”, line 321, in _query conn.query(q) File “D:pythonlibsite-packagespymysqlconnections.py”, line 505, in query self._affected_rows = self._read_query_result(unbuffered=unbuffered) File “D:pythonlibsite-packagespymysqlconnections.py”, line 724, in _read_query_result result.read() File “D:pythonlibsite-packagespymysqlconnections.py”, line 1069, in read first_packet = self.connection._read_packet() File “D:pythonlibsite-packagespymysqlconnections.py”, line 676, in _read_packet packet.raise_for_error() File “D:pythonlibsite-packagespymysqlprotocol.py”, line 223, in raise_for_error err.raise_mysql_exception(self._data) File “D:pythonlibsite-packagespymysqlerr.py”, line 107, in raise_mysql_exception raise errorclass(errno, errval) pymysql.err.ProgrammingError: (1064, “You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘)’ at line 1”) 127.0.0.1 - - [18/Apr/2022 16:53:14] “GET /loginuser=1234&password=1234 HTTP/1.1” 500 - Traceback (most recent call last): File “D:pythonlibsite-packages laskapp.py”, line 2464, in __call__ return self.wsgi_app(environ, start_response) File “D:pythonlibsite-packages laskapp.py”, line 2450, in wsgi_app response = self.handle_exception(e) File “D:pythonlibsite-packages laskapp.py”, line 1867, in handle_exception reraise(exc_type, exc_value, tb) File “D:pythonlibsite-packages lask_compat.py”, line 39, in reraise raise value File “D:pythonlibsite-packages laskapp.py”, line 2447, in wsgi_app response = self.full_dispatch_request() File “D:pythonlibsite-packages laskapp.py”, line 1953, in full_dispatch_request return self.finalize_request(rv) File “D:pythonlibsite-packages laskapp.py”, line 1968, in finalize_request response = self.make_response(rv) File “D:pythonlibsite-packages laskapp.py”, line 2098, in make_response “The view function did not return a valid response. The” TypeError: The view function did not return a valid response. The function either returned None or ended without a return statement. 127.0.0.1 - - [18/Apr/2022 16:53:14] “GET /login__debugger__=yes&cmd=resource&f=style.css HTTP/1.1” 200 - 127.0.0.1 - - [18/Apr/2022 16:53:14] “GET /login__debugger__=yes&cmd=resource&f=jquery.js HTTP/1.1” 200 - 127.0.0.1 - - [18/Apr/2022 16:53:14] “GET /login__debugger__=yes&cmd=resource&f=debugger.js HTTP/1.1” 200 - 127.0.0.1 - - [18/Apr/2022 16:53:14] “GET /login__debugger__=yes&cmd=resource&f=ubuntu.ttf HTTP/1.1” 200 - 127.0.0.1 - - [18/Apr/2022 16:53:14] “GET /login__debugger__=yes&cmd=resource&f=console.png HTTP/1.1” 200 -

注意到这个标红的地方，sql语句，我判断，可能是sql语句写错了，没办法往下执行。

db = pymysql.connect(host=“localhost”, user=“root”, password=“1234”, database=“testdb”)

cursor = db.cursor()

sql = “select * from user where user=” + request.args.get(‘user’) + " and password=" + request.args.get(‘password’)+“)”

我注意到sql语句后面有个多的括号，把他删除

再次运行：

成功跳到下一个页面了。

调错完毕。

先自我介绍一下，小编13年上师交大毕业，曾经在小公司待过，去过华为OPPO等大厂，18年进入阿里，直到现在。深知大多数初中级java工程师，想要升技能，往往是需要自己摸索成长或是报班学习，但对于培训机构动则近万元的学费，着实压力不小。自己不成体系的自学效率很低又漫长，而且容易碰到天花板技术停止不前。因此我收集了一份《java开发全套学习资料》送给大家，初衷也很简单，就是希望帮助到想自学又不知道该从何学起的朋友，同时减轻大家的负担。添加下方名片，即可获取全套学习资料哦