pandas.Series.cat.remove_unused_categories — pandas 2.2.3 documentation (original) (raw)

Series.cat.remove_unused_categories(*args, **kwargs)[source]#

Remove categories which are not used.

Returns:

Categorical

Categorical with unused categories dropped.

Examples

c = pd.Categorical(['a', 'c', 'b', 'c', 'd']) c ['a', 'c', 'b', 'c', 'd'] Categories (4, object): ['a', 'b', 'c', 'd']

c[2] = 'a' c[4] = 'c' c ['a', 'c', 'a', 'c', 'c'] Categories (4, object): ['a', 'b', 'c', 'd']

c.remove_unused_categories() ['a', 'c', 'a', 'c', 'c'] Categories (2, object): ['a', 'c']