def find_all_tiltgroups(fileList):
    """ Find all unique ID codes for each tilt group in the dataset and return them as a list for use:
            [ "tilt_id_1", "tilt_id_2", ... "tilt_id_n"]
    """
    tilt_ids = []
    for file in fileList:
        filename_to_list = file.split("_")
        tilt_id = filename_to_list[3]
        if not tilt_id in tilt_ids:
            tilt_ids.append(tilt_id)
    print(" %s tilt groups found in dataset" % len(tilt_ids))
    return tilt_ids