Flask a web framework that can be used to build web apps with Python.

It’s very minimalist and lightweight, great for making a SaaS app.

Related course: Python Flask: Make Web Apps with Python

Flask Example

First install Flask, you can do so with pip.
Once installed copy the file below and save as web.py

from flask import Flask

app = Flask(__name__)

def helloIndex():
return 'Hello World from Python Flask!'

app.run(host='', port= 81)

Start with:

python web.py

Python will show:

# python web.py 
* Running on (Press CTRL+C to quit)

This means you have a web server running on port 81.

Open your web browser and type

This will show you the hello world message.

Flask hello world


We defined the route (‘/hello’) and mapped it to a function:

def helloIndex():
return 'Hello World from Python Flask!'

If you leave it blank you’ll have the index route.

Download examples