@classmethod
def from_file(cls, filename, hdu_hdu='HDU_INDEX', hdu_obs='OBS_INDEX'):
    'Create from a FITS file.\n\n        The FITS file must contain both index files.\n\n        Parameters\n        ----------\n        filename : str, Path\n            FITS filename\n        hdu_hdu : str or int\n            FITS HDU name or number for the HDU index table\n        hdu_obs : str or int\n            FITS HDU name or number for the observation index table\n        '
    filename = make_path(filename)
    hdu_table = HDUIndexTable.read(filename, hdu=hdu_hdu, format='fits')
    obs_table = ObservationTable.read(filename, hdu=hdu_obs, format='fits')
    return cls(hdu_table=hdu_table, obs_table=obs_table)
Create from a FITS file.

The FITS file must contain both index files.

Parameters
----------
filename : str, Path
    FITS filename
hdu_hdu : str or int
    FITS HDU name or number for the HDU index table
hdu_obs : str or int
    FITS HDU name or number for the observation index table
@classmethod
def from_file(cls, filename, hdu_hdu='HDU_INDEX', hdu_obs='OBS_INDEX'):
    'Create from a FITS file.\n\n        The FITS file must contain both index files.\n\n        Parameters\n        ----------\n        filename : str, Path\n            FITS filename\n        hdu_hdu : str or int\n            FITS HDU name or number for the HDU index table\n        hdu_obs : str or int\n            FITS HDU name or number for the observation index table\n        '
    filename = make_path(filename)
    hdu_table = HDUIndexTable.read(filename, hdu=hdu_hdu, format='fits')
    obs_table = ObservationTable.read(filename, hdu=hdu_obs, format='fits')
    return cls(hdu_table=hdu_table, obs_table=obs_table)