Validation form not working

from flask import Flask, g, render_template, flash, redirect, url_for
from flask_login import LoginManager

import forms
import models

app = Flask(__name__)
app.secret_key = "76^Xdadsadsadasdsa_^"

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 database before each request"""
    g.db = models.DATABASE
    g.db.connect()


@app.after_request
def after_request(response):
    """Close the database 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("Successful registration", "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 "Hi"



if __name__ == "__main__":
    models.initialize()
    try:
        models.User.create_user(
            username="usernamehere",
            email="email@email.com",
            password="password",
            admin=True)
    except ValueError:
        pass

    app.run(debug=True,port=5500)

from flask_wtf import Form
from wtforms import StringField, PasswordField
from wtforms.validators import DataRequired, Regexp, ValidationError, Email, Length, EqualTo

from models import User

def name_exists(form, field):
    if User.select().where(User.username == field.data).exists():
        raise ValidationError("User with that name already exists")


def email_exists(form, field):
    if User.select().where(User.email == field.data).exists():
        raise ValidationError("User with that email already exists")


class RegisterForm(Form):
    username = StringField(
        "Username",
        validators=[
        DataRequired(),
        Regexp(
            r'^[a-zA-Z0-9_]+$', message=("Username should be one word, letters, "
            "numbers and underscores only")
        ),
        name_exists
        ])

    email = StringField(
        "Email",
        validators=[DataRequired(),
        Email(),
        email_exists
        ])
    password = PasswordField(
    "Password",
    validators=[DataRequired(),
    Length(min=2),
    EqualTo("password2",message="Passwords must match") 
            ])
    password2 = PasswordField(
        "Confirm Password",
        validators=[DataRequired()]
        )

{% macro render_field(field) %}
<div class="field">
{% if field.errors %}
    {% for errors in field.errors %}
        <div class="notification error">{{ error }}</div>
    {% endfor %}
{%  endif %}
{{ field(placeholder=field.label.text) }}
</div>
{% endmacro %}

{% from "macros.html" import render_field %}
<form method="POST" action="" class="form">
    {{ form.hidden_tag() }}
    {% for field in form %}
        {{ render_field(field) }}
    {% endfor %}
    <button type="submit" id="submit">Register</button>
</form>

import datetime
from flask_login import UserMixin
from flask_bcrypt import generate_password_hash
from peewee import *



DATABASE = SqliteDatabase("social.db")

class User(UserMixin, Model):
    username = CharField(unique=True)
    email = CharField(unique=True)
    password = CharField(max_length=100)
    joined_at = DateTimeField(default=datetime.datetime.now) #datetime.datetime.now() will set time to WHEN     script is run, don't use paranthesis
is_admin = BooleanField(default=False)

    class Meta:
        database = DATABASE
        order_by = ("-joined_at",)

    @classmethod
    def create_user(cls, username, email, password, admin=False):
        try:
            cls.create(
                username=username,
                email=email,
                password=generate_password_hash(password),
                is_admin=admin)
        except IntegrityError:
            raise ValueError("User already exists")

def initialize():
    DATABASE.connect()
    DATABASE.create_tables([User], safe=True)
    DATABASE.close()