Ubuntu – TypeError: 'Flask' object is not iterable

Encountering difficulties in hosting my Flask application on Ubuntu on AWS due to a persistent error that I’m unable to resolve. The error, identified in the Gunicorn logs, specifically points to a TypeError where the ‘Flask’ object is not iterable. The issue seems to be associated with the handling of the request for the favicon.ico file.

[2023-12-29 22:32:39 +0000] [5686] [ERROR] Error handling request /favicon.ico
Traceback (most recent call last):
  File "/home/ubuntu/venv/lib/python3.10/site-packages/gunicorn/workers/sync.py", line 135, in handle
    self.handle_request(listener, req, client, addr)
  File "/home/ubuntu/venv/lib/python3.10/site-packages/gunicorn/workers/sync.py", line 183, in handle_request
    for item in respiter:
TypeError: 'Flask' object is not iterable

main.py

from myAPP import create_app
from flask_mail import Mail

app = create_app()

@app.template_filter('custom_b64encode')
def custom_b64encode(data):
    return base64.b64encode(data).decode('utf-8')

from flask import render_template

@app.errorhandler(404)
def not_found_error(error):
    return render_template('404.html'), 404


from myAPP.views import views
app.register_blueprint(views, name='my_views')


app.config['UPLOAD_FOLDER'] = '/photos/'

if __name__ == '__main__':
    app.run()

__init__.py

db = SQLAlchemy()
DB_NAME = "database.db"
mail = Mail()  # Initialize mail

def create_app(environ=None, start_response=None):
    
    app = Flask(__name__)
    app.config['SQLALCHEMY_DATABASE_URI'] = f'sqlite:///{DB_NAME}'
    mail = Mail(app)
    app.config['SECRET_KEY'] = 'SecretKey'
    app.config['SECURITY_PASSWORD_SALT'] = 'SecurityPasswordSalt'
    
    app.config['MAIL_SERVER'] = 'example.home.pl'
 
    app.config['MAIL_PORT'] = 587
  
    app.config['MAIL_USE_TLS'] = True  # Enable TLS
    
    app.config['MAIL_USE_SSL'] = False  # Keep SSL disabled
    app.config['MAIL_USERNAME'] = os.environ.get('MAIL_USERNAME', 'username')

    app.config['MAIL_PASSWORD'] = os.environ.get('MAIL_PASSWORD', 'password')
 
    app.config['MAIL_DEFAULT_SENDER'] = '[email protected]'
 
    db.init_app(app)

    mail.init_app(app)  

    with app.app_context():
        db.create_all()

    from .views import views
    from .auth import auth

    app.register_blueprint(views, url_prefix='/')
    app.register_blueprint(auth, url_prefix='/')

    from .models import User, Photo

    login_manager = LoginManager()
    login_manager.login_view = 'auth.loginPage'
    login_manager.init_app(app)

    @login_manager.user_loader
    def load_user(id):
        return User.query.get(int(id))
    
    from . import models

    with app.app_context():
        db.create_all()
    return app

app = create_app()
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER

s = URLSafeTimedSerializer(app.config['SECRET_KEY'])

As a beginner, I tried engaging with chatGPT using the entire database, but faced issues and couldn’t achieve the desired results.