pandas.CategoricalIndex.add_categories

CategoricalIndex.add_categories(*args, **kwargs)

Add new categories.

new_categories will be included at the last/highest place in the categories and will be unused directly after this call.

Parameters

new_categoriescategory or list-like of category

The new categories to be included.

Returns

Categorical

Categorical with new categories added.

Raises

ValueError

If the new categories include old categories or do not validate as categories

See also

rename_categories

Rename categories.

reorder_categories

Reorder categories.

remove_categories

Remove the specified categories.

remove_unused_categories

Remove categories which are not used.

set_categories

Set the categories to the specified ones.

Examples

>>> c = pd.Categorical(['c', 'b', 'c'])
>>> c
['c', 'b', 'c']
Categories (2, object): ['b', 'c']

>>> c.add_categories(['d', 'a'])
['c', 'b', 'c']
Categories (4, object): ['b', 'c', 'd', 'a']