A minimal Flask application

Let's see what a minimal Flask application looks like:

from flask import Flask
app = Flask(__name__)
@app.route('/')
def index():
  return 'Hello World!'

That's it, we are done with the minimal Flask application. It's very simple to configure and create a microservice with Flask.

Let's discuss what exactly the preceding code is doing and how we would run the program:

1. First, we imported a Flask class.
2. Next, we created an instance of the Flask class. This instance will be our WSGI application. This first argument will be the name of the module or package. Here, we created a single module, hence we used __name__. This is needed so that Flask knows where to look for templates, static, and other directories.
3. Then, we used app.route as a decorator with a URL name as a parameter. This will define and map the route with...