CategoricalIndex.
remove_unused_categories
Remove categories which are not used.
Whether or not to drop unused categories inplace or return a copy of this categorical with unused categories dropped.
Deprecated since version 3.2.0.
Categorical with unused categories dropped or None if inplace=True.
inplace=True
See also
rename_categories
Rename categories.
reorder_categories
Reorder categories.
add_categories
Add new categories.
remove_categories
Remove the specified categories.
set_categories
Set the categories to the specified ones.
Examples
>>> idx = ps.CategoricalIndex(list("abbccc"), categories=['a', 'b', 'c', 'd']) >>> idx CategoricalIndex(['a', 'b', 'b', 'c', 'c', 'c'], categories=['a', 'b', 'c', 'd'], ordered=False, dtype='category')
>>> idx.remove_unused_categories() CategoricalIndex(['a', 'b', 'b', 'c', 'c', 'c'], categories=['a', 'b', 'c'], ordered=False, dtype='category')