code: def _load_defaults(self):
          
          self._defaults_module_path = self.defaults_path or \
              '.'.join(self.__module_path_split[:-1]) + ".defaults"
  
          module = self._do_import(self._defaults_module_path)
          self._defaults = {
              k: v for k, v in module.__dict__.items()
              if k.isupper()
          }
docs: Called by ``__init__()`` to create a dictionary of the relevant
          values from the associated defaults module, and save it to the
          object's ``_defaults`` attribute to improve lookup performance.
          Only variables with upper-case names are included.
  
          :raises: ImportError
  
          It is assumed that the defaults module is defined in the same directory
          as ``settings.py`` where the settings helper class is defined. But,
          in cases where this differs, developers can specify an alternative
          import path using the ``defaults_path`` class attribute for their
          helper class.