PaperParser/app/__init__.py

from flask import Flask

from config import config
from app.blueprints import blueprints
from app.extensions import db, migrate
from app.celery import celery_init_app

def create_app(config_class=config):
    app = Flask(__name__)
    app.config.from_object(config_class)

    db.init_app(app)
    migrate.init_app(app)

    for blueprint in blueprints:
        app.register_blueprint(blueprint)
    
    celery_init_app(app)

    return app