pandas.CategoricalIndex.add_categories

CategoricalIndex.add_categories(new_categories)

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']