pandas.Series.cat.remove_unused_categories

Series.cat.remove_unused_categories(*args, **kwargs)

Removes categories which are not used.

Parameters:	inplace : boolean (default: False) Whether or not to drop unused categories inplace or return a copy of this categorical with unused categories dropped.
Returns:	cat : Categorical with unused categories dropped or None if inplace.

See also

rename_categories, reorder_categories, add_categories, remove_categories, set_categories