Why isn’t error login handling working in flask?

Solution
@app.route('/login', methods=['GET', 'POST'])
def login():
    form = LoginForm()
    if form.validate_on_submit():
        user = User.query.filter_by(username=form.username.data).first()
        # username was found
        if user:
            # password is correct
            if bcrypt.check_password_hash(user.password, form.password.data):
                login_user(user)
                return redirect(url_for('dashboard'))
            # password is wrong
            else:
                print("Login Unsuccessful, Please check password")
        # username was not found
        else:
            print('Login Unsuccessful. Please check username')

    return render_template('login.html', form=form)