def __init__(self, data=None, header=None, *args, **kwargs):
        if header is None:
            header = Header()
        self._header = header
        self._file = None
        self._buffer = None
        self._header_offset = None
        self._data_offset = None
        self._data_size = None

        # This internal variable is used to track whether the data attribute
        # still points to the same data array as when the HDU was originally
        # created (this does not track whether the data is actually the same
        # content-wise)
        self._data_replaced = False
        self._data_needs_rescale = False
        self._new = True
        self._output_checksum = False

        if 'DATASUM' in self._header and 'CHECKSUM' not in self._header:
            self._output_checksum = 'datasum'
        elif 'CHECKSUM' in self._header:
            self._output_checksum = True
dataset/ETHPy150Open spacetelescope/PyFITS/pyfits/hdu/base.py/_BaseHDU.__init__/original