pandas.CategoricalIndex.rename_categories

CategoricalIndex.rename_categories(self, *args, **kwargs)

Rename categories.

Parameters:

new_categories : list-like, dict-like or callable

• list-like: all items must be unique and the number of items in the new categories must match the existing number of categories.

• dict-like: specifies a mapping from old categories to new. Categories not contained in the mapping are passed through and extra categories in the mapping are ignored.

  New in version 0.21.0.

• callable : a callable that is called on all items in the old categories and whose return values comprise the new categories.

  New in version 0.23.0.

inplace : bool, default False

Whether or not to rename the categories inplace or return a copy of this categorical with renamed categories.

Returns:

cat : Categorical or None

With inplace=False, the new categorical is returned. With inplace=True, there is no return value.

Raises:

ValueError

If new categories are list-like and do not have the same number of items than the current categories or do not validate as categories

See also

reorder_categories

add_categories

remove_categories

remove_unused_categories

set_categories

Examples

>>> c = pd.Categorical(['a', 'a', 'b'])
>>> c.rename_categories([0, 1])
[0, 0, 1]
Categories (2, int64): [0, 1]

For dict-like new_categories, extra keys are ignored and categories not in the dictionary are passed through

>>> c.rename_categories({'a': 'A', 'c': 'C'})
[A, A, b]
Categories (2, object): [A, b]

You may also provide a callable to create the new categories

>>> c.rename_categories(lambda x: x.upper())
[A, A, B]
Categories (2, object): [A, B]