Flask/Hello World

This lesson shows how to display Hello world using Flask.

1. Wikipedia: Flask (web framework)

1. Create or modify the Flask application page.
   • On Repl.it, modify main.py to include the following code. On your own system, create a new file named app.py with the following code.
     import flask

app = flask.Flask(__name__)

@app.route('/')
def root():
    return "Hello world!"

if __name__ == "__main__":
    app.run(host='0.0.0.0', port=5000)
2. Run the program. On your own system use the following command in a terminal window in the same folder as your app.py file:
   flask run
3. Refresh the output window or open a browser window to http://localhost:5000.
4. Stop the program.