from flask import Flask
import os

def create_app():
    app = Flask(__name__)
    if "SQLALCHEMY_DATABASE_URI" in os.environ.keys():
        app.config['SQLALCHEMY_DATABASE_URI'] = os.environ['SQLALCHEMY_DATABASE_URI']
    from models import db
    db.init_app(app)
    from flask_migrate import Migrate
    migrate = Migrate(app, db)
    from flask_migrate import upgrade
    with app.app_context():
        upgrade(directory="migrations")
    return app