examples/tensorflow/translation/run_translation.py/postprocess_text
def main():
    # region Argument parsing
    # See all possible arguments in src/transformers/training_args.py
    # or by passing the --help flag to this script.
    # We now keep distinct sets of args, for a cleaner separation of concerns.

    parser = HfArgumentParser((ModelArguments, DataTrainingArguments, TFTrainingArguments))
    if len(sys.argv) == 2 and sys.argv[1].endswith(".json"):
        # If we pass only one argument to the script and it's the path to a json file,
        # let's parse it to get our arguments.
        model_args, data_args, training_args = parser.parse_json_file(json_file=os.path.abspath(sys.argv[1]))
    else:
        model_args, data_args, training_args = parser.parse_args_into_dataclasses()

    # Sending telemetry. Tracking the example usage helps us better allocate resources to maintain them. The
    # information sent is the one passed as arguments along with your Python/PyTorch versions.
    send_example_telemetry("run_translation", model_args, data_args, framework="tensorflow")
    # endregion

    # region Logging
    logging.basicConfig(
        format="%(asctime)s - %(levelname)s - %(name)s - %(message)s",
        datefmt="%m/%d/%Y %H:%M:%S",
        handlers=[logging.StreamHandler(sys.stdout)],
    )
    logger.setLevel(logging.INFO)
    datasets.utils.logging.set_verbosity(logging.INFO)
    transformers.utils.logging.set_verbosity(logging.INFO)

    # Log on each process the small summary:
    logger.info(f"Training/evaluation parameters {training_args}")
    # endregion

    # region Detecting last checkpoint
    last_checkpoint = None
    if os.path.isdir(training_args.output_dir) and training_args.do_train and not training_args.overwrite_output_dir:
        last_checkpoint = get_last_checkpoint(training_args.output_dir)
        if last_checkpoint is None and len(os.listdir(training_args.output_dir)) > 0:
            raise ValueError(
                f"Output directory ({training_args.output_dir}) already exists and is not empty. "
                "Use --overwrite_output_dir to overcome."
            )
        elif last_checkpoint is not None and training_args.resume_from_checkpoint is None:
            logger.info(
                f"Checkpoint detected, resuming training at {last_checkpoint}. To avoid this behavior, change "
                "the `--output_dir` or add `--overwrite_output_dir` to train from scratch."
            )
    # endregion

    # Set seed before initializing model.
    set_seed(training_args.seed)

    # region Load datasets
    # Get the datasets: you can either provide your own CSV/JSON training and evaluation files (see below)
    # or just provide the name of one of the public datasets available on the hub at https://huggingface.co/datasets/
    # (the dataset will be downloaded automatically from the datasets Hub).
    #
    # For CSV/JSON files this script will use the first column for the full texts and the second column for the
    # summaries (unless you specify column names for this with the `text_column` and `summary_column` arguments).
    #
    # In distributed training, the load_dataset function guarantee that only one local process can concurrently
    # download the dataset.
    if data_args.dataset_name is not None:
        # Downloading and loading a dataset from the hub.
        raw_datasets = load_dataset(
            data_args.dataset_name,
            data_args.dataset_config_name,
            cache_dir=model_args.cache_dir,
            use_auth_token=True if model_args.use_auth_token else None,
        )
    else:
        data_files = {}
        if data_args.train_file is not None:
            data_files["train"] = data_args.train_file
            extension = data_args.train_file.split(".")[-1]
        if data_args.validation_file is not None:
            data_files["validation"] = data_args.validation_file
            extension = data_args.validation_file.split(".")[-1]
        raw_datasets = load_dataset(
            extension,
            data_files=data_files,
            cache_dir=model_args.cache_dir,
            use_auth_token=True if model_args.use_auth_token else None,
        )
    # See more about loading any type of standard or custom dataset (from files, python dict, pandas DataFrame, etc) at
    # https://huggingface.co/docs/datasets/loading_datasets.html.
    # endregion

    # region Load model config and tokenizer
    #
    # Distributed training:
    # The .from_pretrained methods guarantee that only one local process can concurrently
    # download model & vocab.

    config = AutoConfig.from_pretrained(
        model_args.config_name if model_args.config_name else model_args.model_name_or_path,
        cache_dir=model_args.cache_dir,
        revision=model_args.model_revision,
        use_auth_token=True if model_args.use_auth_token else None,
    )
    tokenizer = AutoTokenizer.from_pretrained(
        model_args.tokenizer_name if model_args.tokenizer_name else model_args.model_name_or_path,
        cache_dir=model_args.cache_dir,
        use_fast=model_args.use_fast_tokenizer,
        revision=model_args.model_revision,
        use_auth_token=True if model_args.use_auth_token else None,
    )

    prefix = data_args.source_prefix if data_args.source_prefix is not None else ""
    # endregion

    # region Dataset preprocessing
    # We need to tokenize inputs and targets.
    if training_args.do_train:
        column_names = raw_datasets["train"].column_names
    elif training_args.do_eval:
        column_names = raw_datasets["validation"].column_names
    else:
        logger.info("There is nothing to do. Please pass `do_train`, and/or `do_eval`.")
        return

    column_names = raw_datasets["train"].column_names

    # For translation we set the codes of our source and target languages (only useful for mBART, the others will
    # ignore those attributes).
    if isinstance(tokenizer, tuple(MULTILINGUAL_TOKENIZERS)):
        assert data_args.target_lang is not None and data_args.source_lang is not None, (
            f"{tokenizer.__class__.__name__} is a multilingual tokenizer which requires --source_lang and "
            "--target_lang arguments."
        )
        tokenizer.src_lang = data_args.source_lang
        tokenizer.tgt_lang = data_args.target_lang
        forced_bos_token_id = (
            tokenizer.lang_code_to_id[data_args.forced_bos_token] if data_args.forced_bos_token is not None else None
        )

    # Get the language codes for input/target.
    source_lang = data_args.source_lang.split("_")[0]
    target_lang = data_args.target_lang.split("_")[0]

    padding = "max_length" if data_args.pad_to_max_length else False

    # Temporarily set max_target_length for training.
    max_target_length = data_args.max_target_length
    padding = "max_length" if data_args.pad_to_max_length else False

    def preprocess_function(examples):
        inputs = [ex[source_lang] for ex in examples["translation"]]
        targets = [ex[target_lang] for ex in examples["translation"]]
        inputs = [prefix + inp for inp in inputs]
        model_inputs = tokenizer(inputs, max_length=data_args.max_source_length, padding=padding, truncation=True)

        # Tokenize targets with the `text_target` keyword argument
        labels = tokenizer(text_target=targets, max_length=max_target_length, padding=padding, truncation=True)

        # If we are padding here, replace all tokenizer.pad_token_id in the labels by -100 when we want to ignore
        # padding in the loss.
        if padding == "max_length" and data_args.ignore_pad_token_for_loss:
            labels["input_ids"] = [
                [(l if l != tokenizer.pad_token_id else -100) for l in label] for label in labels["input_ids"]
            ]

        model_inputs["labels"] = labels["input_ids"]
        return model_inputs

    if training_args.do_train:
        if "train" not in raw_datasets:
            raise ValueError("--do_train requires a train dataset")
        train_dataset = raw_datasets["train"]
        if data_args.max_train_samples is not None:
            max_train_samples = min(len(train_dataset), data_args.max_train_samples)
            train_dataset = train_dataset.select(range(max_train_samples))
        with training_args.main_process_first(desc="train dataset map pre-processing"):
            train_dataset = train_dataset.map(
                preprocess_function,
                batched=True,
                num_proc=data_args.preprocessing_num_workers,
                remove_columns=column_names,
                load_from_cache_file=not data_args.overwrite_cache,
                desc="Running tokenizer on train dataset",
            )
    else:
        train_dataset = None

    if training_args.do_eval:
        max_target_length = data_args.val_max_target_length
        if "validation" not in raw_datasets:
            raise ValueError("--do_eval requires a validation dataset")
        eval_dataset = raw_datasets["validation"]
        if data_args.max_eval_samples is not None:
            max_eval_samples = min(len(eval_dataset), data_args.max_eval_samples)
            eval_dataset = eval_dataset.select(range(max_eval_samples))
        with training_args.main_process_first(desc="validation dataset map pre-processing"):
            eval_dataset = eval_dataset.map(
                preprocess_function,
                batched=True,
                num_proc=data_args.preprocessing_num_workers,
                remove_columns=column_names,
                load_from_cache_file=not data_args.overwrite_cache,
                desc="Running tokenizer on validation dataset",
            )
    else:
        eval_dataset = None
    # endregion

    with training_args.strategy.scope():
        # region Prepare model
        model = TFAutoModelForSeq2SeqLM.from_pretrained(
            model_args.model_name_or_path,
            config=config,
            cache_dir=model_args.cache_dir,
            revision=model_args.model_revision,
            use_auth_token=True if model_args.use_auth_token else None,
        )

        # We resize the embeddings only when necessary to avoid index errors. If you are creating a model from scratch
        # on a small vocab and want a smaller embedding size, remove this test.
        embeddings = model.get_input_embeddings()

        # Matt: This is a temporary workaround as we transition our models to exclusively using Keras embeddings.
        #       As soon as the transition is complete, all embeddings should be keras.Embeddings layers, and
        #       the weights will always be in embeddings.embeddings.
        if hasattr(embeddings, "embeddings"):
            embedding_size = embeddings.embeddings.shape[0]
        else:
            embedding_size = embeddings.weight.shape[0]
        if len(tokenizer) > embedding_size:
            model.resize_token_embeddings(len(tokenizer))

        if isinstance(tokenizer, tuple(MULTILINGUAL_TOKENIZERS)):
            model.config.forced_bos_token_id = forced_bos_token_id
        # endregion

        # region Set decoder_start_token_id
        if model.config.decoder_start_token_id is None and isinstance(tokenizer, (MBartTokenizer, MBartTokenizerFast)):
            assert (
                data_args.target_lang is not None and data_args.source_lang is not None
            ), "mBart requires --target_lang and --source_lang"
            if isinstance(tokenizer, MBartTokenizer):
                model.config.decoder_start_token_id = tokenizer.lang_code_to_id[data_args.target_lang]
            else:
                model.config.decoder_start_token_id = tokenizer.convert_tokens_to_ids(data_args.target_lang)

        if model.config.decoder_start_token_id is None:
            raise ValueError("Make sure that `config.decoder_start_token_id` is correctly defined")
        # endregion

        # region Prepare TF Dataset objects
        label_pad_token_id = -100 if data_args.ignore_pad_token_for_loss else tokenizer.pad_token_id
        data_collator = DataCollatorForSeq2Seq(
            tokenizer,
            model=model,
            label_pad_token_id=label_pad_token_id,
            pad_to_multiple_of=64,  # Reduce the number of unique shapes for XLA, especially for generation
            return_tensors="np",
        )
        num_replicas = training_args.strategy.num_replicas_in_sync
        total_train_batch_size = training_args.per_device_train_batch_size * num_replicas
        total_eval_batch_size = training_args.per_device_eval_batch_size * num_replicas

        dataset_options = tf.data.Options()
        dataset_options.experimental_distribute.auto_shard_policy = tf.data.experimental.AutoShardPolicy.OFF

        # model.prepare_tf_dataset() wraps a Hugging Face dataset in a tf.data.Dataset which is ready to use in
        # training. This is the recommended way to use a Hugging Face dataset when training with Keras. You can also
        # use the lower-level dataset.to_tf_dataset() method, but you will have to specify things like column names
        # yourself if you use this method, whereas they are automatically inferred from the model input names when
        # using model.prepare_tf_dataset()
        # For more info see the docs:
        # https://huggingface.co/docs/transformers/main/en/main_classes/model#transformers.TFPreTrainedModel.prepare_tf_dataset
        # https://huggingface.co/docs/datasets/main/en/package_reference/main_classes#datasets.Dataset.to_tf_dataset

        tf_train_dataset = model.prepare_tf_dataset(
            train_dataset,
            collate_fn=data_collator,
            batch_size=total_train_batch_size,
            shuffle=True,
        ).with_options(dataset_options)
        tf_eval_dataset = model.prepare_tf_dataset(
            eval_dataset, collate_fn=data_collator, batch_size=total_eval_batch_size, shuffle=False
        ).with_options(dataset_options)
        # endregion

        # region Optimizer and LR scheduling
        num_train_steps = int(len(tf_train_dataset) * training_args.num_train_epochs)
        if training_args.warmup_steps > 0:
            num_warmup_steps = training_args.warmup_steps
        elif training_args.warmup_ratio > 0:
            num_warmup_steps = int(num_train_steps * training_args.warmup_ratio)
        else:
            num_warmup_steps = 0
        if training_args.do_train:
            optimizer, lr_schedule = create_optimizer(
                init_lr=training_args.learning_rate,
                num_train_steps=num_train_steps,
                num_warmup_steps=num_warmup_steps,
                adam_beta1=training_args.adam_beta1,
                adam_beta2=training_args.adam_beta2,
                adam_epsilon=training_args.adam_epsilon,
                weight_decay_rate=training_args.weight_decay,
                adam_global_clipnorm=training_args.max_grad_norm,
            )
        else:
            optimizer = None
        # endregion

        # region Metric and postprocessing
        if training_args.do_eval:
            metric = evaluate.load("sacrebleu")

            if data_args.val_max_target_length is None:
                data_args.val_max_target_length = data_args.max_target_length

            gen_kwargs = {
                "max_length": data_args.val_max_target_length,
                "num_beams": data_args.num_beams,
                "no_repeat_ngram_size": 0,  # Not supported under XLA right now, and some models set it by default
            }

            def postprocess_text(preds, labels):
                preds = [pred.strip() for pred in preds]
                labels = [[label.strip()] for label in labels]

                return preds, labels

            def compute_metrics(preds):
                predictions, labels = preds
                if isinstance(predictions, tuple):
                    predictions = predictions[0]
                decoded_preds = tokenizer.batch_decode(predictions, skip_special_tokens=True)
                labels = np.where(labels != -100, labels, tokenizer.pad_token_id)
                decoded_labels = tokenizer.batch_decode(labels, skip_special_tokens=True)
                decoded_preds, decoded_labels = postprocess_text(decoded_preds, decoded_labels)
                metrics = metric.compute(predictions=decoded_preds, references=decoded_labels)
                return {"bleu": metrics["score"]}

            # The KerasMetricCallback allows metrics that are too complex to write as standard Keras metrics
            # to be computed each epoch. Any Python code can be included in the metric_fn. This is especially
            # useful for metrics like BLEU and ROUGE that perform string comparisons on decoded model outputs.
            # For more information, see the docs at
            # https://huggingface.co/docs/transformers/main_classes/keras_callbacks#transformers.KerasMetricCallback

            metric_callback = KerasMetricCallback(
                metric_fn=compute_metrics,
                eval_dataset=tf_eval_dataset,
                predict_with_generate=True,
                use_xla_generation=True,
                generate_kwargs=gen_kwargs,
            )
            callbacks = [metric_callback]
        else:
            callbacks = []

        # endregion

        # region Preparing push_to_hub and model card
        push_to_hub_model_id = training_args.push_to_hub_model_id
        model_name = model_args.model_name_or_path.split("/")[-1]
        if not push_to_hub_model_id:
            push_to_hub_model_id = f"{model_name}-finetuned-{data_args.source_lang}-{data_args.target_lang}"

        model_card_kwargs = {"finetuned_from": model_args.model_name_or_path, "tasks": "translation"}
        if data_args.dataset_name is not None:
            model_card_kwargs["dataset_tags"] = data_args.dataset_name
            if data_args.dataset_config_name is not None:
                model_card_kwargs["dataset_args"] = data_args.dataset_config_name
                model_card_kwargs["dataset"] = f"{data_args.dataset_name} {data_args.dataset_config_name}"
            else:
                model_card_kwargs["dataset"] = data_args.dataset_name

        languages = [l for l in [data_args.source_lang, data_args.target_lang] if l is not None]
        if len(languages) > 0:
            model_card_kwargs["language"] = languages

        if training_args.push_to_hub:
            # Because this training can be quite long, we save once per epoch.
            callbacks.append(
                PushToHubCallback(
                    output_dir=training_args.output_dir,
                    hub_model_id=push_to_hub_model_id,
                    hub_token=training_args.push_to_hub_token,
                    tokenizer=tokenizer,
                    **model_card_kwargs,
                )
            )
        # endregion

        # region Training
        eval_metrics = None
        model.compile(optimizer=optimizer, jit_compile=training_args.xla)

        if training_args.do_train:
            logger.info("***** Running training *****")
            logger.info(f"  Num examples = {len(train_dataset)}")
            logger.info(f"  Num Epochs = {training_args.num_train_epochs}")
            logger.info(f"  Instantaneous batch size per device = {training_args.per_device_train_batch_size}")
            logger.info(f"  Total train batch size = {total_train_batch_size}")
            logger.info(f"  Total optimization steps = {num_train_steps}")

            if training_args.xla and not data_args.pad_to_max_length:
                logger.warning(
                    "XLA training may be slow at first when --pad_to_max_length is not set "
                    "until all possible shapes have been compiled."
                )

            history = model.fit(tf_train_dataset, epochs=int(training_args.num_train_epochs), callbacks=callbacks)
            eval_metrics = {key: val[-1] for key, val in history.history.items()}
        # endregion

        # region Validation
        if training_args.do_eval and not training_args.do_train:
            # Compiling generation with XLA yields enormous speedups, see https://huggingface.co/blog/tf-xla-generate
            @tf.function(jit_compile=True)
            def generate(**kwargs):
                return model.generate(**kwargs)

            if training_args.do_eval:
                logger.info("Evaluation...")
                for batch, labels in tf_eval_dataset:
                    batch.update(gen_kwargs)
                    generated_tokens = generate(**batch)
                    if isinstance(generated_tokens, tuple):
                        generated_tokens = generated_tokens[0]
                    decoded_preds = tokenizer.batch_decode(generated_tokens, skip_special_tokens=True)
                    labels = np.where(labels != -100, labels, tokenizer.pad_token_id)
                    decoded_labels = tokenizer.batch_decode(labels, skip_special_tokens=True)
                    decoded_preds, decoded_labels = postprocess_text(decoded_preds, decoded_labels)

                    metric.add_batch(predictions=decoded_preds, references=decoded_labels)

                eval_metrics = metric.compute()
                logger.info({"bleu": eval_metrics["score"]})
        # endregion

        if training_args.output_dir is not None and eval_metrics is not None:
            output_eval_file = os.path.join(training_args.output_dir, "all_results.json")
            with open(output_eval_file, "w") as writer:
                writer.write(json.dumps(eval_metrics))

        if training_args.output_dir is not None and not training_args.push_to_hub:
            # If we're not pushing to hub, at least save a local copy when we're done
            model.save_pretrained(training_args.output_dir)