Python Flask – Hello World

Hello everyone, In this post, you will learn, How to write simple Hello World example in Python Flask framework. The example program has been tested and shared in the same post.

Example Program

from flask import Flask

app = Flask(__name__)

def hello():
    return 'Hello World'


 * Serving Flask app "app" (lazy loading)
 * Environment: production
   WARNING: Do not use the development server in a production environment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on (Press CTRL+C to quit) - - [01/Feb/2019 12:37:06] "GET / HTTP/1.1" 200 
Python Flask – Hello World