How can I detect if Python is running in Python Development Mode?

Question

To turn on Python Development Mode, you can use this flag:

python3 -X dev example.py

or use this environment variable:

PYTHONDEVMODE=1 python3 example.py

How can I write code within example.py to detect whether Python is running in Python Development Mode or not?

Answer 1

sys.flags.dev_mode is True, when running as python -X dev app.py