@property
    def is_blank(self):

        if not self._verified:
            # The card image has not been parsed yet; compare directly with the
            # string representation of a blank card
            return self._image == BLANK_CARD

        # If the keyword, value, and comment are all empty (for self.value
        # explicitly check that it is a string value, since a blank value is
        # returned as '')
        return (not self.keyword and
                (isinstance(self.value, string_types) and not self.value) and
                not self.comment)
`True` if the card is completely blank--that is, it has no keyword,
dataset/ETHPy150Open spacetelescope/PyFITS/pyfits/card.py/Card.is_blank