<filename>app/__init__.py
from flask import Flask
from flask_bootstrap import Bootstrap
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager
from config import config_options

db=SQLAlchemy()
bootstrap=Bootstrap()
login_manager=LoginManager()
login_manager.session_protection="strong"
login_manager.login_view="auth.login"

def create_app(config_name):
    app=Flask(__name__)
    app.config.from_object(config_options[config_name])
    bootstrap.init_app(app)
    db.init_app(app)
    login_manager.init_app(app)
    # blueprints
    from app.main import main
    from app.auth import auth
    app.register_blueprint(main)
    app.register_blueprint(auth,url_prefix="/auth")
    return app

<filename>app/__init__.py
from flask import Flask
from flask_bootstrap import Bootstrap
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager
from config import config_options

db=SQLAlchemy()
bootstrap=Bootstrap()
login_manager=LoginManager()
login_manager.session_protection="strong"
login_manager.login_view="auth.login"

def create_app(config_name):
    app=Flask(__name__)
    app.config.from_object(config_options[config_name])
    bootstrap.init_app(app)
    db.init_app(app)
    login_manager.init_app(app)
    # blueprints
    from app.main import main
    from app.auth import auth
    app.register_blueprint(main)
    app.register_blueprint(auth,url_prefix="/auth")
    return app

# blueprints