def _iter_content_files(dir_path, alts):
    for alt in alts:
        if alt == PRIMARY_ALT:
            continue
        if os.path.isfile(os.path.join(dir_path, 'contents+%s.lr' % alt)):
            yield alt
    if os.path.isfile(os.path.join(dir_path, 'contents.lr')):
        yield PRIMARY_ALT
:return:
dataset/ETHPy150Open lektor/lektor/lektor/db.py/_iter_content_files--crossover with--dataset/ETHPy150Open ODM2/ODMToolsPython/odmtools/odmservices/series_service.py/SeriesService.get_all_plot_values