code: def main():
      parser = argparse.ArgumentParser(
          description="Replaces out-of-vocabulary words in both source and target "
          "sequences with tokens that indicate the position of the word "
          "in the source sequence."
      )
      parser.add_argument(
          "--source",
          type=str,
          help="text file with source sequences",
          required=True,
      )
      parser.add_argument(
          "--target",
          type=str,
          help="text file with target sequences",
          default=None,
      )
      parser.add_argument(
          "--vocab", type=str, help="vocabulary file", required=True
      )
      parser.add_argument(
          "--source-out",
          type=str,
          help="where to write source sequences with <unk-N> entries",
          required=True,
      )
      parser.add_argument(
          "--target-out",
          type=str,
          help="where to write target sequences with <unk-N> entries",
          default=None,
      )
      args = parser.parse_args()
  
      with open(args.vocab, encoding="utf-8") as vocab:
          vocabulary = vocab.read().splitlines()
  
      target_in = (
          open(args.target, "r", encoding="utf-8")
          if args.target is not None
          else None
      )
      target_out = (
          open(args.target_out, "w", encoding="utf-8")
          if args.target_out is not None
          else None
      )
      with open(args.source, "r", encoding="utf-8") as source_in, open(
          args.source_out, "w", encoding="utf-8"
      ) as source_out:
          replace_oovs(
              source_in, target_in, vocabulary, source_out, target_out
          )
      if target_in is not None:
          target_in.close()
      if target_out is not None:
          target_out.close()
  
label_desc: Use image node_id 2 for calling a global function with example usage: main() without return types