Flask application doesn't take into account the arguments in app.run()?

Question

I have this issue : I use arguments to set the port and the debugger on like this

if __name__ == '__main__':
    app.run(port=4200, debug=True)

but it isn't taken into account when I click on the run button (I use Pycharm pro and the project I create is a Flask Project)

The terminal shows this :

FLASK_APP = app.py
FLASK_ENV = development
FLASK_DEBUG = 0
In folder $FOLDERPATH
$PATH\python.exe -m flask run
 * Serving Flask app 'app.py' (lazy loading)
 * Environment: development
 * Debug mode: off
 * Running on http://127.0.0.1:5000 (Press CTRL+C to quit)

Any ideas ?

Answer 1

Your call to app.run is only relevant when __name__ == __main__...that is, when your code is the main entrypoint. But as you can see from the terminal output, Pycharm isn't calling python app.py, it is in fact calling:

python -m flask run

In this case, the flask module is the main entrypoint, and you would control things like the port or debug mode through environment variables (like FLASK_DEBUG) or command line parameters (python -m flask run --port 4200).

According to the pycharm documentation, you can see command line parameters for the flask run command using the "Additional options" field.