Run a Flask app in production or development/debug from the command line

flaskserver.py

""" 
    Run a Flask app in production or development/debug from the command line

    If you wish to run a Flask app with Python instead of the `flask run` command,
    this code provides an easier way to decide if you want to run it in production
    or debug mode.

    Usage: 
    python flaskserver.py dev        # runs with debug set to True
    python flaskserver.py            # production mode

"""
  
import sys
from flask import Flask

app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello, world!"

if __name__ == '__main__':
    is_debug = False

    if len(sys.argv) > 1 and sys.argv[1] == 'dev':
        is_debug = True
        
    app.run(debug=is_debug)