Installation

$ pip install flask

$ flask --version
Python 3.7.3
Flask 1.1.1
Werkzeug 0.15.5

Creating a App

Create base python script app.py

from flask import Flask

app = Flask(__name__)

@app.route('/')
def example():
   return '{"name":"Bob"}'

if __name__ == '__main__':
    app.run()

Start Flask

flask run

 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
127.0.0.1 - - [01/Aug/2019 12:19:00] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [01/Aug/2019 12:19:00] "GET /favicon.ico HTTP/1.1" 404 -