pandas.api.extensions.ExtensionArray._values_for_factorize#
- ExtensionArray._values_for_factorize()[source]#
Return an array and missing value suitable for factorization.
- Returns
- valuesndarray
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_valueobject
The value in values to consider missing. This will be treated as NA in the factorization routines, so it will be coded as na_sentinel 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()
.