首页 > 解决方案 > Flask-Login 未注册用户给出 500 错误

问题描述

我正在尝试按照 github 上的代码示例制作一个简单的 Flask 登录服务器。它适用于程序中的用户,但如果输入的用户名不正确,则会出现 500 内部服务器错误。任何建议都会很棒:)

@app.route('/login', methods=['GET', 'POST'])
def login():
    if flask.request.method == 'GET':
        return '''
               <form action='login' method='POST'>
                <input type='text' name='email' id='username' placeholder='email'/>
                <input type='password' name='password' id='password' placeholder='password'/>
                <input type='submit' name='submit'/>
               </form>
               '''
               #return render_template('logins.html')
    # if request.method == 'POST':
        # username = request.form['username']
        # password = request.form['password']

    email = flask.request.form['email']
    if flask.request.form['password'] == users[email]['password']:
        user = User()
        user.id = email
        flask_login.login_user(user)
        return flask.redirect(flask.url_for('protected'))
    return 'Bad login'



    Traceback (most recent call last):
  File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 2446, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1951, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1820, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python3.5/dist-packages/flask/_compat.py", line 39, in reraise
    raise value
  File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1949, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1935, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "serv.py", line 65, in login
    if flask.request.form['password'] == users[email]['password']:
KeyError: 's'

标签: flaskflask-login

解决方案


请编辑您的问题以添加错误回溯和您的代码以确保完整性。

根据您提到的行为,我可以进行粗略的推测。你应该有 user_loader 回调函数,你在使用之前使用它来获取用户login_user(user)。根据您的实现,此函数可能会从数据库或内存字典或列表中加载用户

如果您从字典加载,您很可能没有异常处理,以防用户不存在的实例,您的代码应如下所示。

@login_manager.user_loader
def load_user(userid):
    try:
        user = users[userid]
        return user
    except KeyError:
        return None

上面的代码处理异常并None在用户不存在的情况下返回。这就是为什么flask-login能够决定不让您的用户登录,而您的程序不会返回错误。


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