python - 'NoneType' object has no attribute 'username'? -

so got error

attributeerror: 'nonetype' object has no attribute 'username'

any suggestions,

models.py

class user(db.model):     __tablename__ = "users"     id = db.column(db.integer, primary_key=true)     username = db.column(db.string(80), unique=true)     password = db.column(db.string(20), unique=true)       def __init__(self, username, password):         self.username = username         self.password= bcrypt.generate_password_hash(password, 10)         def is_authenticated(self):         return true       def is_active(self):         return true      def is_anonymous(self):         return false      def get_id(self):         return (self.id)       def __repr__(self):         return '<user %r>' % self.username 

views.py

@app.route('/register', methods=['get','post']) def register():     if request.method == 'get':         return render_template('register.html')     user = user(request.form['username'] , request.form['password'] )     username = request.form['username']     password = request.form['password']     storeduser = user.query.filter_by(username=username).first()     if storeduser.username not none , storeduser.username == request.form['username']:         return 'user exist !'     else:         db.session.add(user)         db.session.commit()         flash('user registered')         return redirect(url_for('index')) 

pretty if client username matches current username output existing user registered, if not register username.

im referring username in models(in case wondering)

the user.query.filter_by(username=username).first() query returned none, meaning user not found.

you need test if storeduser not none first, not storeduser.username:

if storeduser not none , storeduser.username == request.form['username']:     return 'user exist !' 

because queried on request.form['username'] latter test redundant, need use;

if storeduser not none:     return 'user exist !'