SMS Birthday Card Step 1: Write boilerplate to create Flask application.

app.py

from flask import Flask
import os


app = Flask(__name__)


if __name__ == '__main__':
    port = int(os.environ.get('PORT', 5000))

    if port == 5000:
        app.debug = True

    app.run(host='0.0.0.0', port=port)