[Fixed]-Django testing without email backend

You don’t need to define the EMAIL_BACKEND setting (it has a default), but you do need to define a setting module. You can set the DJANGO_SETTINGS_MODULE in your shell environment, or set os.environ['DJANGO_SETTINGS_MODULE'] to point to your settings module.

Note that calling python manage.py shell will set up the Django environment for you, which includes setting DJANGO_SETTINGS_MODULE and calling django.setup(). You still need to call setup_test_environment() to manually run tests in your python shell.