pandas.Series.cat.remove_unused_categories#

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

Remove categories which are not used.

Returns:

Categorical

Categorical with unused categories dropped.

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

>>>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']