code: def _parse_tsv(path, language_pair=None):
    
    if language_pair is None:
      lang_match = re.match(r".*\.([a-z][a-z])-([a-z][a-z])\.tsv", path)
      assert lang_match is not None, "Invalid TSV filename: %s" % path
      l1, l2 = lang_match.groups()
    else:
      l1, l2 = language_pair
    with tf.io.gfile.GFile(path) as f:
      for j, line in enumerate(f):
        cols = line.split("\t")
        if len(cols) != 2:
          logging.warning(
              "Skipping line %d in TSV (%s) with %d != 2 columns.",
              j, path, len(cols))
          continue
        s1, s2 = cols
        yield {
            l1: s1.strip(),
            l2: s2.strip()
        }
docs: Generates examples from TSV file.