code: def reindex(self, target, method=None, level=None, limit=None,
                  tolerance=None):
          
          # GH6552: preserve names when reindexing to non-named target
          # (i.e. neither Index nor Series).
          preserve_names = not hasattr(target, 'name')
  
          # GH7774: preserve dtype/tz if target is empty and not an Index.
          target = _ensure_has_len(target)  # target may be an iterator
  
          if not isinstance(target, Index) and len(target) == 0:
              attrs = self._get_attributes_dict()
              attrs.pop('freq', None)  # don't preserve freq
              values = self._data[:0]  # appropriately-dtyped empty array
              target = self._simple_new(values, dtype=self.dtype, **attrs)
          else:
              target = ensure_index(target)
  
          if level is not None:
              if method is not None:
                  raise TypeError('Fill method not supported if level passed')
              _, indexer, _ = self._join_level(target, level, how='right',
                                               return_indexers=True)
          else:
              if self.equals(target):
                  indexer = None
              else:
  
                  if self.is_unique:
                      indexer = self.get_indexer(target, method=method,
                                                 limit=limit,
                                                 tolerance=tolerance)
                  else:
                      if method is not None or limit is not None:
                          raise ValueError("cannot reindex a non-unique index "
                                           "with a method or limit")
                      indexer, missing = self.get_indexer_non_unique(target)
  
          if preserve_names and target.nlevels == 1 and target.name != self.name:
              target = target.copy()
              target.name = self.name
  
          return target, indexer
docs: Create index with target's values (move/add/delete values
          as necessary).
  
          Parameters
          ----------
          target : an iterable
  
          Returns
          -------
          new_index : pd.Index
              Resulting index.
          indexer : np.ndarray or None
              Indices of output values in original index.