Get the codes.

        Returns
        -------
        codes : integer array view
            A non writable view of the `codes` array.

def _get_codes(self):
        """
        Get the codes.

        Returns
        -------
        codes : integer array view
            A non writable view of the `codes` array.
        """
        v = self._codes.view()
        v.flags.writeable = False
        return v