def create_vocab_tables(src_vocab_file):
  """Creates vocab tables for src_vocab_file and tgt_vocab_file."""
  src_vocab_table = lookup_ops.index_table_from_file(
      src_vocab_file, default_value=UNK_ID)
  tgt_vocab_table = src_vocab_table
  return src_vocab_table, tgt_vocab_table