The Flask Mega-Tutorial, Part I: Hello, World!

Abstraction: Flask web application setup tutorial covering installation and Hello World app

Key points:

• Recommends using Python virtual environments (python3 -m venv venv) to isolate package versions per project, avoiding global installation conflicts
• Flask 3.x used in the 2024 edition; install via pip install flask inside activated venv
• Application structured as a Python package (app/) with __init__.py creating the Flask instance and a routes.py module defining view functions
• Routes mapped via @app.route decorators; flask run starts dev server on port 5000 by default
• FLASK_APP environment variable tells Flask which module to import; python-dotenv + .flaskenv file automates this across sessions
• 23-chapter series covering templates, forms, database, auth, deployment (Linux/Heroku/Docker), APIs, and more

Connections: Flask · Miguel Grinberg · Web Development · Python · Virtual Environments

Source: http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-i-hello-world