pandas.api.extensions.ExtensionArray.factorize#

ExtensionArray.factorize(na_sentinel=_NoDefault.no_default, use_na_sentinel=_NoDefault.no_default)[source]#

Encode the extension array as an enumerated type.

Parameters
na_sentinelint, default -1

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

Deprecated since version 1.5.0: The na_sentinel argument is deprecated and will be removed in a future version of pandas. Specify use_na_sentinel as either True or False.

use_na_sentinelbool, default True

If True, the sentinel -1 will be used for NaN values. If False, NaN values will be encoded as non-negative integers and will not drop the NaN from the uniques of the values.

New in version 1.5.0.

Returns
codesndarray

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

uniquesExtensionArray

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.