old_contents: #!/usr/bin/env python
  from darts.app import db
  
  class User(db.Model):
      """ Create user table"""
      id = db.Column(db.Integer, primary_key=True)
      username = db.Column(db.String(100), unique=True)
      password = db.Column(db.String(100))
  
      def __init__(self, username, password):
          self.username = username
          self.password = password
  
  
  if __name__ == "__main__":
      db.create_all()
  
new_contents: from flask_sqlalchemy import SQLAlchemy
  
  db = SQLAlchemy()
  
  class User(db.Model):
      """ Create user table"""
      id = db.Column(db.Integer, primary_key=True)
      username = db.Column(db.String(100), unique=True)
      password = db.Column(db.String(100))
  
      def __init__(self, username, password):
          self.username = username
          self.password = password
  
  
  if __name__ == "__main__":
      from flask import Flask
  
      app = Flask(__name__)
      app.config.from_pyfile('app.config')
  
      db.init_app(app)
      db.create_all(app=app)
  
subject: fix models.py