pandas.Categorical.from_codes#

classmethodCategorical.from_codes(codes,categories=None,ordered=None,dtype=None,validate=True)[source]#

Make a Categorical type from codes and categories or dtype.

This constructor is useful if you already have codes andcategories/dtype and so do not need the (computation intensive)factorization step, which is usually done on the constructor.

If your data does not follow this convention, please use the normalconstructor.

Parameters:

codesarray-like of int

An integer array, where each integer points to a category incategories or dtype.categories, or else is -1 for NaN.

categoriesindex-like, optional

The categories for the categorical. Items need to be unique.If the categories are not given here, then they must be providedindtype.

orderedbool, optional

Whether or not this categorical is treated as an orderedcategorical. If not given here or indtype, the resultingcategorical will be unordered.

dtypeCategoricalDtype or “category”, optional

IfCategoricalDtype, cannot be used together withcategories orordered.

validatebool, default True

If True, validate that the codes are valid for the dtype.If False, don’t validate that the codes are valid. Be careful about skippingvalidation, as invalid codes can lead to severe problems, such as segfaults.

Added in version 2.1.0.

Returns:

Categorical

Examples

>>>dtype=pd.CategoricalDtype(['a','b'],ordered=True)>>>pd.Categorical.from_codes(codes=[0,1,0,1],dtype=dtype)['a', 'b', 'a', 'b']Categories (2, object): ['a' < 'b']