pandas.api.extensions.ExtensionArray._values_for_factorize¶
-
ExtensionArray.
_values_for_factorize
(self) → Tuple[numpy.ndarray, Any][source]¶ Return an array and missing value suitable for factorization.
Returns: - values : ndarray
An array suitable for factorization. This should maintain order and be a supported dtype (Float64, Int64, UInt64, String, Object). By default, the extension array is cast to object dtype.
- na_value : object
The value in values to consider missing. This will be treated as NA in the factorization routines, so it will be coded as na_sentinal and not included in uniques. By default,
np.nan
is used.
Notes
The values returned by this method are also used in
pandas.util.hash_pandas_object()
.