def __getattr__( self, n ):
            """Defer applying class defaults until they are actually needed"""
            try: result = _kwds[n]
            except KeyError:
                if n in _slots:
                    result = None
                else: raise
            object.__setattr__( self, n, result )
            return result
Defer applying class defaults until they are actually needed
recipes/Python/577473_Named_Sequences_environments_containing_large/recipe-577473.py