models.py

from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, BooleanField
from wtforms.validators import InputRequired, Length
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user, current_user

db = SQLAlchemy()

login_man = LoginManager()
login_man.login_view = 'login'

class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(15), unique=True)
    password = db.Column(db.String(80))

@login_man.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))

# --------------------------
class LoginForm(FlaskForm):
    username = StringField('Username', validators=[InputRequired(), Length(min=4, max=15)])
    password = PasswordField('Password', validators=[InputRequired(), Length(min=8, max=80)])
    remember_session = BooleanField('Remember session')

# ---------------------------
class RegisterForm(FlaskForm):
    username = StringField('Username', validators=[InputRequired(), Length(min=4, max=15)])
    password = PasswordField('Password', validators=[InputRequired(), Length(min=8, max=80)])