Why does running the Flask dev server run itself twice?

Question

I\'m using Flask for developing a website and while in development I run flask using the following file:

#!/usr/bin/env python
from datetime import datetime
         


        

Answer 1

From Flask 0.11, it's recommended to run your app with flask run rather than python application.py. Using the latter could result in running your code twice.

As stated here :

... from Flask 0.11 onwards the flask method is recommended. The reason for this is that due to how the reload mechanism works there are some bizarre side-effects (like executing certain code twice...)