code: def arctic_setting(setting_name, valid_options=None):
      
      try:
          value = getattr(settings, setting_name)
          if valid_options and value not in valid_options:
              error_message = "Invalid value for {}, must be one of: {}".format(
                  setting_name, str(valid_options)
              )
              raise ImproperlyConfigured(error_message)
      except AttributeError:
          pass
      return getattr(settings, setting_name, getattr(defaults, setting_name))
docs: Tries to get a setting from the django settings, if not available defaults
      to the one defined in defaults.py