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:

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.

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.

The values returned by this method are also used in pandas.util.hash_pandas_object().

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Licensed under the 3-clause BSD License.
https://pandas.pydata.org/pandas-docs/version/0.25.0/reference/api/pandas.api.extensions.ExtensionArray._values_for_factorize.html