def _start_writing_raw(name, info, sel=None, data_type=FIFF.FIFFT_FLOAT,
                       reset_range=True):
    #
    #    Measurement info
    #
    info = pick_info(info, sel)

    #
    #  Create the file and save the essentials
    #
    fid = start_file(name)
    start_block(fid, FIFF.FIFFB_MEAS)
    write_id(fid, FIFF.FIFF_BLOCK_ID)
    if info['meas_id'] is not None:
        write_id(fid, FIFF.FIFF_PARENT_BLOCK_ID, info['meas_id'])

    cals = []
    for k in range(info['nchan']):
        #
        #   Scan numbers may have been messed up
        #
        info['chs'][k]['scanno'] = k + 1  # scanno starts at 1 in FIF format
        if reset_range is True:
            info['chs'][k]['range'] = 1.0
        cals.append(info['chs'][k]['cal'] * info['chs'][k]['range'])

    write_meas_info(fid, info, data_type=data_type, reset_range=reset_range)

    #
    # Start the raw data
    #
    if info.get('maxshield', False):
        start_block(fid, FIFF.FIFFB_SMSH_RAW_DATA)
    else:
        start_block(fid, FIFF.FIFFB_RAW_DATA)

    return fid, cals
Construct a datastore index instance.
dataset/ETHPy150Open mne-tools/mne-python/mne/io/base.py/_start_writing_raw--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/datastore.py/_BaseIndex.__init__