Flask is a favorite library for web application development in Python. It is simple, light weight and fast growing library and privides extensive area in web application development. If you want to know more about Flask please read the documentation from here Flask

Prerequisite

  1. Python installed in your machine
  2. PIP installed in your machine

Note: I am using MacOS. If you use windows then some command might be change

Lets start..

Make a new directory

Make a directory to install Flask app

    $ mkdir FlaskApp
    $ cd FlaskApp

Create virtual environment for our project

To create virtual environment please execute this command

    $ python -m venv virtual
    # Here virtual is a name. You can named it anything

Activate virtual env

    $ source virtual/bin/activate
    # Here virtual is my virtual env name. If your env is another name then used that name

Install Flask

    $ pip install flask

Create an python file to write our first route for App

    $ touch app.py

Initialize the Flask App

Write folling code in app.py file.

    from flask import Flask
    # Create a Flask Instance
    app = Flask(__name__)

    # Create a route decorator
    @app.route('/')
    def index():
        return "<h1>This is Home page</h1>"

Congratulation!! We have created our first route. Now If we can run our local server then We can see our app.

Run the Flask App

To run the app we need to export the app.py Please execute following commands serially

    $ export FLASK_APP=app.py   
    $ flask run

If everything is fine then a local server will start in http://127.0.0.1:5000 address. If we browse this in our browser then we can see our text “This is Home page”

Congratulation!! You have successfully install and run the Flask App. Note: If you want to deactivate the virtual env then simply type deactivate.

Happy Coding :)