import tensorflow as tf

                    clean_pairs = cleaner_en_xx.clean_en_xx_pairs(clean_pairs)
                  for source, target in clean_pairs:
                    if source and target:
                      lang1_resfile.write(source)
                      lang1_resfile.write("\n")
                      lang2_resfile.write(target)
                      lang2_resfile.write("\n")

        else:
          lang1_filename, lang2_filename = dataset[1]
          lang1_filepath = os.path.join(tmp_dir, lang1_filename)
          lang2_filepath = os.path.join(tmp_dir, lang2_filename)
          is_sgm = (
              lang1_filename.endswith("sgm") and lang2_filename.endswith("sgm"))

          if not (tf.gfile.Exists(lang1_filepath) and
                  tf.gfile.Exists(lang2_filepath)):
            # For .tar.gz and .tgz files, we read compressed.
            mode = "r:gz" if compressed_filepath.endswith("gz") else "r"
            with tarfile.open(compressed_filepath, mode) as corpus_tar:
              corpus_tar.extractall(tmp_dir)
          if lang1_filepath.endswith(".gz"):
            new_filepath = lang1_filepath.strip(".gz")
            generator_utils.gunzip_file(lang1_filepath, new_filepath)
            lang1_filepath = new_filepath
          if lang2_filepath.endswith(".gz"):
            new_filepath = lang2_filepath.strip(".gz")
            generator_utils.gunzip_file(lang2_filepath, new_filepath)
            lang2_filepath = new_filepath

