code: def tabbed_parsing_token_generator(data_dir, tmp_dir, train, prefix,
                                     source_vocab_size, target_vocab_size):
    
    filename = "parsing_{0}.pairs".format("train" if train else "dev")
    source_vocab = generator_utils.get_or_generate_tabbed_vocab(
        data_dir, tmp_dir, filename, 0,
        prefix + "_source.tokens.vocab.%d" % source_vocab_size, source_vocab_size)
    target_vocab = generator_utils.get_or_generate_tabbed_vocab(
        data_dir, tmp_dir, filename, 1,
        prefix + "_target.tokens.vocab.%d" % target_vocab_size, target_vocab_size)
    pair_filepath = os.path.join(tmp_dir, filename)
    return text_problems.text2text_generate_encoded(
        text_problems.text2text_txt_tab_iterator(pair_filepath), source_vocab,
        target_vocab)
docs: Generate source and target data from a single file.