code: def import_from_string(val, setting_name):
      
      try:
          # Nod to tastypie's use of importlib.
          parts = val.split('.')
          module_path, class_name = '.'.join(parts[:-1]), parts[-1]
          module = importlib.import_module(module_path)
          return getattr(module, class_name)
      except (ImportError, AttributeError) as e:
          msg = "Could not import '%s' for Graph Auth setting '%s'. %s: %s." % (val, setting_name, e.__class__.__name__, e)
          raise ImportError(msg)
docs: Attempt to import a class from a string representation.