AttributeError: type object 'User' has no attribute 'get'

Question

I'm trying to run my Flask Application and I keep getting the following Error:

AttributeError: type object 'User' has no attribute 'get'

I'm assuming it's coming from my Models.py code:

class User(db.Model):
    __tablename__ = 'users'
    __table_args__ = {'extend_existing': True} 
    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)
    password = db.Column(db.String(128))
    confirmed = db.Column(db.Boolean, default=False)
    #posts = db.relationship('Post', lazy='dynamic')


    def is_active(self):
        return True

    def get_id(self):
        return self.email

    def is_authenticated(self):
        return self.authenticated

    def is_anonymous(self):
        return False


    @login_manager.user_loader
    def load_user(userid):

        return User.get(User.id==userid)

After playing around, it looks like I may need the following code block somewhere or a variation of?:

def get_object(self):
    return self.request.user

Or some type of derivative of that. Any assistance would be greatly appreciated. Thanks!

Here is the full traceback:

 form = PostForm()
[2018-07-06 11:08:23,652] ERROR in app: Exception on /index [GET]
Traceback (most recent call last):
File 
"/Users.../sqlalchemy/sql/elements.py", line 682, in __getattr__
return getattr(self.comparator, key)
AttributeError: 'Comparator' object has no attribute 'request'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/...python3.6/site-packages/flask/app.py", line 2292, in 
wsgi_app
response = self.full_dispatch_request()
File "/Users/...b/python3.6/site-packages/flask/app.py", line 1815, in 
full_dispatch_request
rv = self.handle_user_exception(e)
File "/Users/...python3.6/site-packages/flask/app.py", line 1718, in 
handle_user_exception
reraise(exc_type, exc_value, tb)
File "/Users//python3.6/site-packages/flask/_compat.py", line 35, in 
reraise
raise value
File "/Users/...python3.6/site-packages/flask/app.py", line 1813, in 
full_dispatch_request
rv = self.dispatch_request()
File "/Users/WilliamStevens//site-packages/flask/app.py", line 1799, in 
dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
 File "/Users//Documents/deplorable_snowflake/.../views.py", line 52, in 
index
return render_template('frontpage.html', form=form, posts=posts)
File "/Users/.../python3.6/site-packages/flask/templating.py", line 133, 
   in render_template
  ctx.app.update_template_context(context)
    File "/Users/W/python3.6/site-packages/flask/app.py", line 792, in 
   update_template_context
   context.update(func())
    File "/Users/.../flask_login/utils.py", line 368, in 
   _user_context_processor
   return dict(current_user=_get_user())
  File "/Users/.../python3.6/site-packages/flask_login/utils.py", line 
  335, 
  in _get_user
  current_app.login_manager._load_user()
  File "/Users/.../python3.6/site- 
  packages/flask_login/login_manager.py", 
  line 359, in _load_user
  return self.reload_user()
  File "/Users/.../lib/python3.6/site- 
  packages/flask_login/login_manager.py", line 321, in reload_user
   user = self.user_callback(user_id)
   File 
  "/Users/.../models.py", line 53, in load_user
  return User.get(User.id==userid)
  File 
 "/Users/WilliamStevens/.../models.py", line 47, in get
 return self.request.user
    File "/Users/...site-packages/sqlalchemy/sql/elements.py", line 688, 
  in 
 __getattr__
  key)
 AttributeError: Neither 'BinaryExpression' object nor 'Comparator' 
 object has an attribute 'request'

Answer 1

Thank you @Nathan Wailes and @shmee. These solutions fixed my issue too.

@will - it's better to inherit UserMixin class along with db.Model class for User model instead of explicitly writing the code for below methods:

• is_active
• is_authenticated
• is_anonymous
• get_id

class User(UserMixin,db.Model):
    __tablename__ = 'users'
    __table_args__ = {'extend_existing': True} 
    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)
    password = db.Column(db.String(128))
    confirmed = db.Column(db.Boolean, default=False)

Then in app.py (main application class), you can add below code before calling the login, logout, etc.., end points:

# It should be placed outside of the class
@login_manager.user_loader
def load_user(userid):
    return User.query.get(userid)

You can refer Flask-Login documentation here: https://flask-login.readthedocs.io/en/latest/

Answer 2

Im working with SQLAlchemy. My User class looks like this

class User(db.Model, UserMixin):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(250), nullable=False)
    email = db.Column(db.String(250), nullable=False, unique=True)
    password = db.Column(db.String(250), nullable=False)

I had this, which gave me the error:

  @login_manager.user_loader
    def load_user(user_id):
        return User.get(id)

And I change it to this:

@login_manager.user_loader
def load_user(user_id):
    return User.query.filter_by(id=user_id).first()

The point of load_user function is to get User object, to load it. I really dont know why User.get(user_id) doesnt work, but I retrieve a row from the table the I usually do.

Answer 3

I just had this problem. shmee's proposed solution is what worked for me:

1. The load_user() function should not be a part of the User class, but instead its own standalone function.
2. The load_user() function should call User.query.get(user_id), not User.get(user_id).
   • I think this confusion comes from the fact that Flask-Login's documentation has it the latter way as of today: return User.get(user_id).

Example code:

class User(db.Model, UserMixin):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False)
    password = db.Column(db.String(80))

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


@login_manager.user_loader
def load_user(user_id):
    return User.query.get(user_id)