python - invalid salt still even when using decode utf -

can tell me im doing wrong, keep getting invalid salt, want hash password using bcrypt. here code

views.py

@app.route('/login',methods=['get','post']) def login():     if request.method == 'get':         return render_template('login.html')      username = request.form['username']     password =request.form['password']     user = user.query.filter_by(username=username).first()     if user , bcrypt.check_password_hash(user.password, request.form['password']):         login_user(user)         session['logged_in'] = true         flash('logged in successfully')         return redirect(request.args.get('next') or url_for('index'))     else:             flash('invalid username or password')         return redirect(url_for('login')) 

models.py

from app import db, bcrypt  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         pwhash = bcrypt.generate_password_hash(password.encode('utf8'), bcrypt.gensalt())         self.password = pwhash.decode('utf8')         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 

i think did right, used salt, used decode utf, keep getting invalid salt, recommendations guys