code: def get_without(self, fragments,
                      use_lookup=None):
          
          if use_lookup is None:
              use_lookup = settings['defaults']['use_lookup']
  
          if pd.api.types.is_list_like(fragments):
              for fragment in fragments:
                  try:
                      index_of_all_fragments |= fragment.index
                  except NameError:
                      index_of_all_fragments = fragment.index
          else:
              index_of_all_fragments = fragments.index
          missing_part = self.loc[self.index.difference(index_of_all_fragments)]
          missing_part = missing_part.fragmentate(use_lookup=use_lookup)
          return sorted(missing_part, key=len, reverse=True)
docs: Return self without the specified fragments.
  
          Args:
              fragments: Either a list of :class:`~chemcoord.Cartesian` or a
                  :class:`~chemcoord.Cartesian`.
              use_lookup (bool): Use a lookup variable for
                  :meth:`~chemcoord.Cartesian.get_bonds`. The default is
                  specified in ``settings['defaults']['use_lookup']``
  
          Returns:
              list: List containing :class:`~chemcoord.Cartesian`.