def normalize(
        self,
        form: str,
    ) -> T_DataArray:
        """
        Return the Unicode normal form for the strings in the datarray.

        For more information on the forms, see the documentation for
        :func:`unicodedata.normalize`.

        Parameters
        ----------
        form : {"NFC", "NFKC", "NFD", "NFKD"}
            Unicode form.

        Returns
        -------
        normalized : same type as values

        """
        return self._apply(func=lambda x: normalize(form, x))  # type: ignore[arg-type]

        Return the Unicode normal form for the strings in the datarray.

        For more information on the forms, see the documentation for
        :func:`unicodedata.normalize`.

        Parameters
        ----------
        form : {"NFC", "NFKC", "NFD", "NFKD"}
            Unicode form.

        Returns
        -------
        normalized : same type as values

        
xarray/core/accessor_str.py