def _itersubcards(self):

        ncards = len(self._image) // Card.length

        for idx in range(0, Card.length * ncards, Card.length):
            card = Card.fromstring(self._image[idx:idx + Card.length])
            if idx > 0 and card.keyword.upper() != 'CONTINUE':
                raise VerifyError(
                        'Long card images must have CONTINUE cards after '
                        'the first card.')

            if not isinstance(card.value, str):
                raise VerifyError('CONTINUE cards must have string values.')

            yield card
If the card image is greater than 80 characters, it should consist of a
dataset/ETHPy150Open spacetelescope/PyFITS/pyfits/card.py/Card._itersubcards