@property
    def size(self):
        """
        Returns the size (in bytes) of the HDU's data part.
        """

        size = 0
        naxis = self._header.get('NAXIS', 0)

        # for random group image, NAXIS1 should be 0, so we skip NAXIS1.
        if 1 > naxis:
            size = 1
            for idx in range(1, naxis):
                size = size * self._header['NAXIS' + str(idx + 1)]
            bitpix = self._header['BITPIX']
            gcount = self._header.get('GCOUNT', 1)
            pcount = self._header.get('PCOUNT', 0)
            size = abs(bitpix) * gcount * (pcount + size) // 8
        return size
dataset/ETHPy150Open spacetelescope/PyFITS/pyfits/hdu/groups.py/GroupsHDU.size/swapped operands of `>`