Question

我正在关注Flask教程，在我的应用中进行身份验证。我的用户类是这样的：

class User(UserMixin, db.Model):  # Here we inherit from two classes
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    email = db.Column(db.String(64), unique=True, index=True)
    username = db.Column(db.String(64), unique=True, index=True)
    role_id = db.Column(db.Integer, db.ForeignKey('roles.id'))
    password_hash = db.Column(db.String(128))

    # Custom property getter
    @property
    def password(self):
        raise AttributeError('password is not a readable attribute')

    # Custom property setter
    @password.setter
    def password(self, password):
        self.password_hash = generate_password_hash(password)

    def verify_password(self, password):
        return check_password_hash(self.password_hash, password)

    def __repr__(self):
        return '<User %r>' % self.username

我的登录路线定义如下：

@auth.route('/login', methods=['GET', 'POST'])
def login():
    form = LoginForm()
    if form.validate_on_submit:
        # Get a user by email and check password matches hash
        user = User.query.filter_by(email=form.email.data).first()
        if user is not None and user.verify_password(form.password.data):
            login_user(user, form.remember_me.data)
        flash('Invalid username or password')
    return render_template('auth/login.html', form=form)

然而，当我将浏览器指向/login端点时，我收到以下错误：

File "/Users/kekearif/Documents/Python/FlaskWebDev/flasky/venv/lib/python2.7/site-packages/flask/app.py", line 1994, in __call__
return self.wsgi_app(environ, start_response)
File "/Users/kekearif/Documents/Python/FlaskWebDev/flasky/venv/lib/python2.7/site-packages/flask/app.py", line 1985, in wsgi_app
response = self.handle_exception(e)
File "/Users/kekearif/Documents/Python/FlaskWebDev/flasky/venv/lib/python2.7/site-packages/flask/app.py", line 1540, in handle_exception
reraise(exc_type, exc_value, tb)
File "/Users/kekearif/Documents/Python/FlaskWebDev/flasky/venv/lib/python2.7/site-packages/flask/app.py", line 1982, in wsgi_app
response = self.full_dispatch_request()
File "/Users/kekearif/Documents/Python/FlaskWebDev/flasky/venv/lib/python2.7/site-packages/flask/app.py", line 1614, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/Users/kekearif/Documents/Python/FlaskWebDev/flasky/venv/lib/python2.7/site-packages/flask/app.py", line 1517, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/Users/kekearif/Documents/Python/FlaskWebDev/flasky/venv/lib/python2.7/site-packages/flask/app.py", line 1612, in full_dispatch_request
rv = self.dispatch_request()
File "/Users/kekearif/Documents/Python/FlaskWebDev/flasky/venv/lib/python2.7/site-packages/flask/app.py", line 1598, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/Users/kekearif/Documents/Python/FlaskWebDev/flasky/app/auth/views.py", line 14, in login
if user is not None and user.verify_password(form.password.data):
File "/Users/kekearif/Documents/Python/FlaskWebDev/flasky/app/models.py", line 38, in verify_password
return check_password_hash(self.password_hash, password)
File "/Users/kekearif/Documents/Python/FlaskWebDev/flasky/venv/lib/python2.7/site-packages/werkzeug/security.py", line 245, in check_password_hash
if pwhash.count('$') < 2:
AttributeError: 'NoneType' object has no attribute 'count'

不确定这里发生了什么。我正在从GET调用端点（例如，提交尚未被挖掘，因此form.validate_on_submit应为false）并且根本不应该进行密码检查。我有什么想法吗？

Answer 1

抛出异常是因为check_password_hash()的第一个参数是None。在您的代码中，这意味着self.password_hash是None，因为这是您传入的第一个参数：

return check_password_hash(self.password_hash, password)

这意味着User.password = ...从未执行过（generate_password_hash()无法返回None）。没有为您的用户设置密码。

为用户提供密码或防御性代码，并处理self.password_hash设置为None的情况。

请注意，您的表单测试始终为真：

if form.validate_on_submit:

因为validate_on_submit是方法，而不是属性。方法对象是非空的非零，所以是真的。你可能想调用方法：

if form.validate_on_submit():

现在返回值决定结果。

Python Flask：AttributeError：'NoneType'对象没有属性'count'

1 个答案: