@property
    def rawvalue(self):

        if self._rawvalue is not None:
            return self._rawvalue
        elif self.field_specifier is not None:
            self._rawvalue = '%s: %s' % (self.field_specifier, self.value)
            return self._rawvalue
        else:
            return self.value
On record-valued keyword cards this is the raw string value in
dataset/ETHPy150Open spacetelescope/PyFITS/pyfits/card.py/Card.rawvalue