pandas.api.extensions.ExtensionArray.factorize

ExtensionArray.factorize(self, na_sentinel: int = -1) → Tuple[numpy.ndarray, pandas.core.dtypes.generic.ABCExtensionArray]

Encode the extension array as an enumerated type.

Parameters:

na_sentinel : int, default -1

Value to use in the labels array to indicate missing values.

Returns:

labels : ndarray

An integer NumPy array that’s an indexer into the original ExtensionArray.

uniques : ExtensionArray

An ExtensionArray containing the unique values of self.

Note

uniques will not contain an entry for the NA value of the ExtensionArray if there are any missing values present in self.

See also

factorize

Top-level factorize method that dispatches here.

Notes

pandas.factorize() offers a sort keyword as well.