CategoricalIndex.join(other, how='left', level=None, return_indexers=False) [source]
this is an internal non-public method Compute join_index and indexers to conform data structures to the new index. Parameters:
other : Index how : {?left?, ?right?, ?inner?, ?outer?} level : int or level name, default None return_indexers : boolean, default False Returns:
join_index, (left_indexer, right_indexer)