Application Setup in Python
From the Flask cheat sheet · Setup & Basics · verified Jul 2026
Application Setup
Create and configure Flask app
python
# Quick Reference
from flask import Flask
app = Flask(__name__)
@app.route('/')
def home():
return 'Hello World!'
if __name__ == '__main__':
app.run(debug=True)💡 Use environment variables for configuration
🔍 Flask(__name__) creates the application instance
⚡ debug=True enables auto-reload and detailed errors
setupconfiguration