Flask social network, Register form error

from flask import (Flask, g, render_template, flash, redirect, url_for)
from flask.ext.login import LoginManager

import forms
import models

DEBUG = True
PORT = 8000
HOST = '0.0.0.0'

app = Flask(__name__)
app.secret_key = 'aiurbg  uogbwg lar h09312 SJDF DH GF497y uhg93 th3 5g35g0u3g595jg83'

login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_view = 'login'

@login_manager.user_loader
def load_user(userid):
  try:
    return models.User.get(models.User.id == userid)
  except models.DoesNotExist:
    return None


@app.before_request
def before_request():
  """Connect to the database before each request"""
  g.db=models.DATABASE
  g.db.connect()


@app.after_request
def after_request(response):
  """Close the databse connection after each request"""
  g.db.close()
  return response


@app.route('/register', methods=('GET', 'POST'))
def register():
    form = forms.RegisterForm()
    if form.validate_on_submit():
        flash("Yay, you registered!", "success")
        models.User.create_user(
            username=form.username.data,
            email=form.email.data,
            password=form.password.data
        )
        return redirect(url_for('index'))
    return render_template('register.html', form=form)

@app.route('/')
def index():
  return 'Wagwan!'


if __name__ == '__main__':
  models.initialize()
  try:
    models.User.create_user(
    username='joshkeenan',
    email='example@example.com',
    password='password',
    admin=True)
  except ValueError:
    pass
  app.run(debug=True, host='0.0.0.0', port=8000)