def split_exists(split, src, tgt, lang, data_path):
    filename = os.path.join(data_path, '{}.{}-{}.{}'.format(split, src, tgt, lang))
    return indexed_dataset.dataset_exists(filename, impl=dataset_impl)
def split_exists(split, src, tgt, lang, data_path):
    filename = os.path.join(data_path, '{}.{}-{}.{}'.format(split, src, tgt, lang))
    return indexed_dataset.dataset_exists(filename, impl=dataset_impl)