Set the categories to the specified new_categories.
new_categories can include new categories (which will result in
unused categories) or remove old categories (which results in values
set to NaN). If rename==True, the categories will simple be renamed
(less or more items than in old categories will result in values set to
NaN or in unused categories respectively).
This method can be used to perform more than one action of adding,
removing, and reordering simultaneously and is therefore faster than
performing the individual steps via the more specialised methods.
On the other hand this methods does not do checks (e.g., whether the
old categories are included in the new categories on a reorder), which
can result in surprising changes, for example when using special string
dtypes, which does not considers a S1 string equal to a single char
The categories in new order.
Whether or not the categorical is treated as a ordered categorical.
If not given, do not change the ordered information.
Whether or not the new_categories should be considered as a rename
of the old categories or as reordered categories.
Whether or not to reorder the categories in-place or return a copy
of this categorical with reordered categories.
If new_categories does not validate as categories
Add new categories.
Remove the specified categories.
Remove categories which are not used.