Folder structure

your_app_folder/
│
├── app.py            # Python Flask application code
├── requirements.txt  # File listing Python dependencies
│
├── templates/        # Folder containing HTML templates
│   └── index.html    # HTML template for the upload page
│
├── static/           # Folder containing static files
│   └── dist/         # Distribution folder for CSS, JS, images, etc.
│       ├── css/     # Compiled CSS files
│       ├── js/      # Compiled JavaScript files
│       └── images/  # Image files
│
└── uploads/          # Folder where uploaded files will be stored temporarily