Example #1
0
def main():
    # 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, TrainingArguments))
    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(
        )

    if (os.path.exists(training_args.output_dir)
            and os.listdir(training_args.output_dir) and training_args.do_train
            and not training_args.overwrite_output_dir):
        raise ValueError(
            f"Output directory ({training_args.output_dir}) already exists and is not empty."
            "Use --overwrite_output_dir to overcome.")

    # Setup logging
    logging.basicConfig(
        format="%(asctime)s - %(levelname)s - %(name)s -   %(message)s",
        datefmt="%m/%d/%Y %H:%M:%S",
    )
    logger.setLevel(logging.INFO if is_main_process(training_args.local_rank
                                                    ) else logging.WARN)

    # Log on each process the small summary:
    logger.warning(
        f"Process rank: {training_args.local_rank}, device: {training_args.device}, n_gpu: {training_args.n_gpu}"
        +
        f"distributed training: {bool(training_args.local_rank != -1)}, 16-bits training: {training_args.fp16}"
    )
    # Set the verbosity to info of the Transformers logger (on main process only):
    if is_main_process(training_args.local_rank):
        transformers.utils.logging.set_verbosity_info()
    logger.info("Training/evaluation parameters %s", training_args)

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

    # Get the datasets: you can either provide your own CSV/JSON/TXT 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 column called 'text' or the first column if no column called
    # 'text' is found. You can easily tweak this behavior (see below).
    #
    # 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.
        datasets = load_dataset(data_args.dataset_name,
                                data_args.dataset_config_name)
    else:
        data_files = {}
        if data_args.train_file is not None:
            data_files["train"] = data_args.train_file
        if data_args.validation_file is not None:
            data_files["validation"] = data_args.validation_file
        extension = data_args.train_file.split(".")[-1]
        datasets = load_dataset(extension, data_files=data_files, field="data")
    # 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.

    # Load pretrained model 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,
    )
    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=True,
    )
    model = AutoModelForQuestionAnswering.from_pretrained(
        model_args.model_name_or_path,
        from_tf=bool(".ckpt" in model_args.model_name_or_path),
        config=config,
        cache_dir=model_args.cache_dir,
    )

    # Tokenizer check: this script requires a fast tokenizer.
    if not isinstance(tokenizer, PreTrainedTokenizerFast):
        raise ValueError(
            "This example script only works for models that have a fast tokenizer. Checkout the big table of models "
            "at https://huggingface.co/transformers/index.html#bigtable to find the model types that meet this "
            "requirement")

    # Preprocessing the datasets.
    # Preprocessing is slighlty different for training and evaluation.
    if training_args.do_train:
        column_names = datasets["train"].column_names
    else:
        column_names = datasets["validation"].column_names
    question_column_name = "question" if "question" in column_names else column_names[
        0]
    context_column_name = "context" if "context" in column_names else column_names[
        1]
    answer_column_name = "answers" if "answers" in column_names else column_names[
        2]

    # Padding side determines if we do (question|context) or (context|question).
    pad_on_right = tokenizer.padding_side == "right"

    # Training preprocessing
    def prepare_train_features(examples):
        # Tokenize our examples with truncation and maybe padding, but keep the overflows using a stride. This results
        # in one example possible giving several features when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.
        tokenized_examples = tokenizer(
            examples[
                question_column_name if pad_on_right else context_column_name],
            examples[
                context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=data_args.max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            padding="max_length" if data_args.pad_to_max_length else False,
        )

        # Since one example might give us several features if it has a long context, we need a map from a feature to
        # its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")
        # The offset mappings will give us a map from token to character position in the original context. This will
        # help us compute the start_positions and end_positions.
        offset_mapping = tokenized_examples.pop("offset_mapping")

        # Let's label those examples!
        tokenized_examples["start_positions"] = []
        tokenized_examples["end_positions"] = []

        for i, offsets in enumerate(offset_mapping):
            # We will label impossible answers with the index of the CLS token.
            input_ids = tokenized_examples["input_ids"][i]
            cls_index = input_ids.index(tokenizer.cls_token_id)

            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            sequence_ids = tokenized_examples.sequence_ids(i)

            # One example can give several spans, this is the index of the example containing this span of text.
            sample_index = sample_mapping[i]
            answers = examples[answer_column_name][sample_index]
            # If no answers are given, set the cls_index as answer.
            if len(answers["answer_start"]) == 0:
                tokenized_examples["start_positions"].append(cls_index)
                tokenized_examples["end_positions"].append(cls_index)
            else:
                # Start/end character index of the answer in the text.
                start_char = answers["answer_start"][0]
                end_char = start_char + len(answers["text"][0])

                # Start token index of the current span in the text.
                token_start_index = 0
                while sequence_ids[token_start_index] != (1 if pad_on_right
                                                          else 0):
                    token_start_index += 1

                # End token index of the current span in the text.
                token_end_index = len(input_ids) - 1
                while sequence_ids[token_end_index] != (1 if pad_on_right else
                                                        0):
                    token_end_index -= 1

                # Detect if the answer is out of the span (in which case this feature is labeled with the CLS index).
                if not (offsets[token_start_index][0] <= start_char
                        and offsets[token_end_index][1] >= end_char):
                    tokenized_examples["start_positions"].append(cls_index)
                    tokenized_examples["end_positions"].append(cls_index)
                else:
                    # Otherwise move the token_start_index and token_end_index to the two ends of the answer.
                    # Note: we could go after the last offset if the answer is the last word (edge case).
                    while token_start_index < len(offsets) and offsets[
                            token_start_index][0] <= start_char:
                        token_start_index += 1
                    tokenized_examples["start_positions"].append(
                        token_start_index - 1)
                    while offsets[token_end_index][1] >= end_char:
                        token_end_index -= 1
                    tokenized_examples["end_positions"].append(
                        token_end_index + 1)

        return tokenized_examples

    if training_args.do_train:
        train_dataset = datasets["train"].map(
            prepare_train_features,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            remove_columns=column_names,
            load_from_cache_file=not data_args.overwrite_cache,
        )

    # Validation preprocessing
    def prepare_validation_features(examples):
        # Tokenize our examples with truncation and maybe padding, but keep the overflows using a stride. This results
        # in one example possible giving several features when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.
        tokenized_examples = tokenizer(
            examples[
                question_column_name if pad_on_right else context_column_name],
            examples[
                context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=data_args.max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            padding="max_length" if data_args.pad_to_max_length else False,
        )

        # Since one example might give us several features if it has a long context, we need a map from a feature to
        # its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")

        # For evaluation, we will need to convert our predictions to substrings of the context, so we keep the
        # corresponding example_id and we will store the offset mappings.
        tokenized_examples["example_id"] = []

        for i in range(len(tokenized_examples["input_ids"])):
            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            sequence_ids = tokenized_examples.sequence_ids(i)
            context_index = 1 if pad_on_right else 0

            # One example can give several spans, this is the index of the example containing this span of text.
            sample_index = sample_mapping[i]
            tokenized_examples["example_id"].append(
                examples["id"][sample_index])

            # Set to None the offset_mapping that are not part of the context so it's easy to determine if a token
            # position is part of the context or not.
            tokenized_examples["offset_mapping"][i] = [
                (o if sequence_ids[k] == context_index else None)
                for k, o in enumerate(tokenized_examples["offset_mapping"][i])
            ]

        return tokenized_examples

    if training_args.do_eval:
        validation_dataset = datasets["validation"].map(
            prepare_validation_features,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            remove_columns=column_names,
            load_from_cache_file=not data_args.overwrite_cache,
        )

    # Data collator
    # We have already padded to max length if the corresponding flag is True, otherwise we need to pad in the data
    # collator.
    data_collator = default_data_collator if data_args.pad_to_max_length else DataCollatorWithPadding(
        tokenizer)

    # Post-processing:
    def post_processing_function(examples, features, predictions):
        # Post-processing: we match the start logits and end logits to answers in the original context.
        predictions = postprocess_qa_predictions(
            examples=examples,
            features=features,
            predictions=predictions,
            version_2_with_negative=data_args.version_2_with_negative,
            n_best_size=data_args.n_best_size,
            max_answer_length=data_args.max_answer_length,
            null_score_diff_threshold=data_args.null_score_diff_threshold,
            output_dir=training_args.output_dir,
            is_world_process_zero=trainer.is_world_process_zero(),
        )
        # Format the result to the format the metric expects.
        if data_args.version_2_with_negative:
            formatted_predictions = [{
                "id": k,
                "prediction_text": v,
                "no_answer_probability": 0.0
            } for k, v in predictions.items()]
        else:
            formatted_predictions = [{
                "id": k,
                "prediction_text": v
            } for k, v in predictions.items()]
        references = [{
            "id": ex["id"],
            "answers": ex[answer_column_name]
        } for ex in datasets["validation"]]
        return EvalPrediction(predictions=formatted_predictions,
                              label_ids=references)

    # TODO: Once the fix lands in a Datasets release, remove the _local here and the squad_v2_local folder.
    current_dir = os.path.sep.join(
        os.path.join(__file__).split(os.path.sep)[:-1])
    metric = load_metric(
        os.path.join(current_dir, "squad_v2_local") if data_args.
        version_2_with_negative else "squad")

    def compute_metrics(p: EvalPrediction):
        return metric.compute(predictions=p.predictions,
                              references=p.label_ids)

    # Initialize our Trainer
    trainer = QuestionAnsweringTrainer(
        model=model,
        args=training_args,
        train_dataset=train_dataset if training_args.do_train else None,
        eval_dataset=validation_dataset if training_args.do_eval else None,
        eval_examples=datasets["validation"]
        if training_args.do_eval else None,
        tokenizer=tokenizer,
        data_collator=data_collator,
        post_process_function=post_processing_function,
        compute_metrics=compute_metrics,
    )

    # Training
    if training_args.do_train:
        train_result = trainer.train(
            model_path=model_args.model_name_or_path if os.path.
            isdir(model_args.model_name_or_path) else None)
        trainer.save_model()  # Saves the tokenizer too for easy upload

        output_train_file = os.path.join(training_args.output_dir,
                                         "train_results.txt")
        if trainer.is_world_process_zero():
            with open(output_train_file, "w") as writer:
                logger.info("***** Train results *****")
                for key, value in sorted(train_result.metrics.items()):
                    logger.info(f"  {key} = {value}")
                    writer.write(f"{key} = {value}\n")

            # Need to save the state, since Trainer.save_model saves only the tokenizer with the model
            trainer.state.save_to_json(
                os.path.join(training_args.output_dir, "trainer_state.json"))

    # Evaluation
    results = {}
    if training_args.do_eval:
        logger.info("*** Evaluate ***")
        results = trainer.evaluate()

        output_eval_file = os.path.join(training_args.output_dir,
                                        "eval_results.txt")
        if trainer.is_world_process_zero():
            with open(output_eval_file, "w") as writer:
                logger.info("***** Eval results *****")
                for key, value in sorted(results.items()):
                    logger.info(f"  {key} = {value}")
                    writer.write(f"{key} = {value}\n")

    return results
Example #2
0
def main():
    # 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, TrainingArguments))
    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(
        )

    # 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."
            )

    # Setup 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 if is_main_process(training_args.local_rank
                                                    ) else logging.WARN)

    # Log on each process the small summary:
    logger.warning(
        f"Process rank: {training_args.local_rank}, device: {training_args.device}, n_gpu: {training_args.n_gpu}"
        +
        f"distributed training: {bool(training_args.local_rank != -1)}, 16-bits training: {training_args.fp16}"
    )
    # Set the verbosity to info of the Transformers logger (on main process only):
    if is_main_process(training_args.local_rank):
        transformers.utils.logging.set_verbosity_info()
        transformers.utils.logging.enable_default_handler()
        transformers.utils.logging.enable_explicit_format()
    logger.info(f"Training/evaluation parameters {training_args}")

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

    # Get the datasets: you can either provide your own CSV/JSON/TXT 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 column called 'text' or the first column if no column called
    # 'text' is found. You can easily tweak this behavior (see below).
    #
    # 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.
        datasets = load_dataset(data_args.dataset_name,
                                data_args.dataset_config_name,
                                cache_dir=model_args.cache_dir)
    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]
        if data_args.test_file is not None:
            data_files["test"] = data_args.test_file
            extension = data_args.test_file.split(".")[-1]
        datasets = load_dataset(extension,
                                data_files=data_files,
                                field="data",
                                cache_dir=model_args.cache_dir)
    # 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.

    # Load pretrained model 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,
        # output_hidden_states = True,
    )
    DE_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,
        output_hidden_states=True,
    )
    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=True,
        revision=model_args.model_revision,
        use_auth_token=True if model_args.use_auth_token else None,
    )
    model = AutoModelForQuestionAnswering.from_pretrained(
        model_args.model_name_or_path,
        from_tf=bool(".ckpt" in 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,
    )

    # Tokenizer check: this script requires a fast tokenizer.
    if not isinstance(tokenizer, PreTrainedTokenizerFast):
        raise ValueError(
            "This example script only works for models that have a fast tokenizer. Checkout the big table of models "
            "at https://huggingface.co/transformers/index.html#bigtable to find the model types that meet this "
            "requirement")

    # Preprocessing the datasets.
    # Preprocessing is slighlty different for training and evaluation.
    if training_args.do_train:
        column_names = datasets["train"].column_names
    elif training_args.do_eval:
        column_names = datasets["validation"].column_names
    else:
        column_names = datasets["test"].column_names
    question_column_name = "question" if "question" in column_names else column_names[
        0]
    context_column_name = "context" if "context" in column_names else column_names[
        1]
    answer_column_name = "answers" if "answers" in column_names else column_names[
        2]

    # Padding side determines if we do (question|context) or (context|question).
    pad_on_right = tokenizer.padding_side == "right"

    if data_args.max_seq_length > tokenizer.model_max_length:
        logger.warning(
            f"The max_seq_length passed ({data_args.max_seq_length}) is larger than the maximum length for the"
            f"model ({tokenizer.model_max_length}). Using max_seq_length={tokenizer.model_max_length}."
        )
    max_seq_length = min(data_args.max_seq_length, tokenizer.model_max_length)

    # Training preprocessing
    def prepare_train_features(examples):
        # Tokenize our examples with truncation and maybe padding, but keep the overflows using a stride. This results
        # in one example possible giving several features when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.
        tokenized_examples = tokenizer(
            examples[
                question_column_name if pad_on_right else context_column_name],
            examples[
                context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            padding="max_length" if data_args.pad_to_max_length else False,
        )

        # Since one example might give us several features if it has a long context, we need a map from a feature to
        # its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")
        # The offset mappings will give us a map from token to character position in the original context. This will
        # help us compute the start_positions and end_positions.
        offset_mapping = tokenized_examples.pop("offset_mapping")

        # Let's label those examples!
        tokenized_examples["start_positions"] = []
        tokenized_examples["end_positions"] = []

        for i, offsets in enumerate(offset_mapping):
            # We will label impossible answers with the index of the CLS token.
            input_ids = tokenized_examples["input_ids"][i]
            cls_index = input_ids.index(tokenizer.cls_token_id)

            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            sequence_ids = tokenized_examples.sequence_ids(i)

            # One example can give several spans, this is the index of the example containing this span of text.
            sample_index = sample_mapping[i]
            answers = examples[answer_column_name][sample_index]
            # If no answers are given, set the cls_index as answer.
            if len(answers["answer_start"]) == 0:
                tokenized_examples["start_positions"].append(cls_index)
                tokenized_examples["end_positions"].append(cls_index)
            else:
                # Start/end character index of the answer in the text.
                start_char = answers["answer_start"][0]
                end_char = start_char + len(answers["text"][0])

                # Start token index of the current span in the text.
                token_start_index = 0
                while sequence_ids[token_start_index] != (1 if pad_on_right
                                                          else 0):
                    token_start_index += 1

                # End token index of the current span in the text.
                token_end_index = len(input_ids) - 1
                while sequence_ids[token_end_index] != (1 if pad_on_right else
                                                        0):
                    token_end_index -= 1

                # Detect if the answer is out of the span (in which case this feature is labeled with the CLS index).
                if not (offsets[token_start_index][0] <= start_char
                        and offsets[token_end_index][1] >= end_char):
                    tokenized_examples["start_positions"].append(cls_index)
                    tokenized_examples["end_positions"].append(cls_index)
                else:
                    # Otherwise move the token_start_index and token_end_index to the two ends of the answer.
                    # Note: we could go after the last offset if the answer is the last word (edge case).
                    while token_start_index < len(offsets) and offsets[
                            token_start_index][0] <= start_char:
                        token_start_index += 1
                    tokenized_examples["start_positions"].append(
                        token_start_index - 1)
                    while offsets[token_end_index][1] >= end_char:
                        token_end_index -= 1
                    tokenized_examples["end_positions"].append(
                        token_end_index + 1)

        return tokenized_examples

    if training_args.do_train:
        if "train" not in datasets:
            raise ValueError("--do_train requires a train dataset")
        train_dataset = datasets["train"]
        if data_args.max_train_samples is not None:
            # We will select sample from whole data if agument is specified
            train_dataset = train_dataset.select(
                range(data_args.max_train_samples))
        # Create train feature from dataset
        train_dataset = train_dataset.map(
            prepare_train_features,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            remove_columns=column_names,
            load_from_cache_file=not data_args.overwrite_cache,
        )
        if data_args.max_train_samples is not None:
            # Number of samples might increase during Feature Creation, We select only specified max samples
            train_dataset = train_dataset.select(
                range(data_args.max_train_samples))

    # Validation preprocessing
    def prepare_validation_features(examples):
        # Tokenize our examples with truncation and maybe padding, but keep the overflows using a stride. This results
        # in one example possible giving several features when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.
        tokenized_examples = tokenizer(
            examples[
                question_column_name if pad_on_right else context_column_name],
            examples[
                context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            padding="max_length" if data_args.pad_to_max_length else False,
        )

        # Since one example might give us several features if it has a long context, we need a map from a feature to
        # its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")

        # For evaluation, we will need to convert our predictions to substrings of the context, so we keep the
        # corresponding example_id and we will store the offset mappings.
        tokenized_examples["example_id"] = []

        for i in range(len(tokenized_examples["input_ids"])):
            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            sequence_ids = tokenized_examples.sequence_ids(i)
            context_index = 1 if pad_on_right else 0

            # One example can give several spans, this is the index of the example containing this span of text.
            sample_index = sample_mapping[i]
            tokenized_examples["example_id"].append(
                examples["id"][sample_index])

            # Set to None the offset_mapping that are not part of the context so it's easy to determine if a token
            # position is part of the context or not.
            tokenized_examples["offset_mapping"][i] = [
                (o if sequence_ids[k] == context_index else None)
                for k, o in enumerate(tokenized_examples["offset_mapping"][i])
            ]

        return tokenized_examples

    if training_args.do_eval:
        if "validation" not in datasets:
            raise ValueError("--do_eval requires a validation dataset")
        eval_examples = datasets["validation"]
        if data_args.max_eval_samples is not None:
            # We will select sample from whole data
            eval_examples = eval_examples.select(
                range(data_args.max_eval_samples))
        # Validation Feature Creation
        eval_dataset = eval_examples.map(
            prepare_validation_features,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            remove_columns=column_names,
            load_from_cache_file=not data_args.overwrite_cache,
        )
        if data_args.max_eval_samples is not None:
            # During Feature creation dataset samples might increase, we will select required samples again
            eval_dataset = eval_dataset.select(
                range(data_args.max_eval_samples))

    if training_args.do_predict:
        if "test" not in datasets:
            raise ValueError("--do_predict requires a test dataset")
        predict_examples = datasets["test"]
        if data_args.max_predict_samples is not None:
            # We will select sample from whole data
            predict_examples = predict_examples.select(
                range(data_args.max_predict_samples))
        # Predict Feature Creation
        predict_dataset = predict_examples.map(
            prepare_validation_features,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            remove_columns=column_names,
            load_from_cache_file=not data_args.overwrite_cache,
        )
        if data_args.max_predict_samples is not None:
            # During Feature creation dataset samples might increase, we will select required samples again
            predict_dataset = predict_dataset.select(
                range(data_args.max_predict_samples))

    # Data collator
    # We have already padded to max length if the corresponding flag is True, otherwise we need to pad in the data
    # collator.
    data_collator = (default_data_collator if data_args.pad_to_max_length else
                     DataCollatorWithPadding(
                         tokenizer,
                         pad_to_multiple_of=8 if training_args.fp16 else None))

    # Post-processing:
    def post_processing_function(examples,
                                 features,
                                 predictions,
                                 stage="eval"):
        # Post-processing: we match the start logits and end logits to answers in the original context.
        predictions = postprocess_qa_predictions(
            examples=examples,
            features=features,
            predictions=predictions,
            version_2_with_negative=data_args.version_2_with_negative,
            n_best_size=data_args.n_best_size,
            max_answer_length=data_args.max_answer_length,
            null_score_diff_threshold=data_args.null_score_diff_threshold,
            output_dir=training_args.output_dir,
            is_world_process_zero=trainer.is_world_process_zero(),
            prefix=stage,
        )
        # Format the result to the format the metric expects.
        if data_args.version_2_with_negative:
            formatted_predictions = [{
                "id": k,
                "prediction_text": v,
                "no_answer_probability": 0.0
            } for k, v in predictions.items()]
        else:
            formatted_predictions = [{
                "id": k,
                "prediction_text": v
            } for k, v in predictions.items()]

        references = [{
            "id": ex["id"],
            "answers": ex[answer_column_name]
        } for ex in examples]
        return EvalPrediction(predictions=formatted_predictions,
                              label_ids=references)

    metric = load_metric(
        "squad_v2" if data_args.version_2_with_negative else "squad")

    def compute_metrics(p: EvalPrediction):
        return metric.compute(predictions=p.predictions,
                              references=p.label_ids)

    # Initialize our Trainer
    # 这里与其他的runqa的不一样,要重新重构
    trainer = QuestionAnsweringTrainer(
        model=model,
        args=training_args,
        train_dataset=train_dataset if training_args.do_train else None,
        eval_dataset=eval_dataset if training_args.do_eval else None,
        eval_examples=eval_examples if training_args.do_eval else None,
        tokenizer=tokenizer,
        data_collator=data_collator,
        post_process_function=post_processing_function,
        compute_metrics=compute_metrics,
    )

    # 用于难度划分
    DE_model = AutoModelForQuestionAnswering.from_pretrained(
        model_args.DE_model,
        from_tf=bool(".ckpt" in model_args.model_name_or_path),
        config=DE_config,
        cache_dir=model_args.cache_dir,
        revision=model_args.model_revision,
        use_auth_token=True if model_args.use_auth_token else None,
    )

    trainer_DE = QATrainer_CL(
        model=DE_model,
        args=training_args,
        train_dataset=change_dataset(train_dataset),
        eval_dataset=eval_dataset if training_args.do_eval else None,
        eval_examples=eval_examples if training_args.do_eval else None,
        tokenizer=tokenizer,
        data_collator=data_collator,
        post_process_function=post_processing_function,
        compute_metrics=compute_metrics,
    )

    curr_subset, train_dataset_ordered = DE(trainer_DE, train_dataset,
                                            training_args, data_args)
    curr_subset.insert(0, train_dataset_ordered)

    training_args_curr = copy.deepcopy(training_args)
    training_args_curr.num_train_epochs = 1
    trainer_curr = []
    for i in range(data_args.div_subset):
        trainer_curr.append(
            QuestionAnsweringTrainer(
                model=model,
                args=training_args_curr,
                train_dataset=curr_subset[i]
                if training_args.do_train else None,
                eval_dataset=eval_dataset if training_args.do_eval else None,
                eval_examples=eval_examples if training_args.do_eval else None,
                tokenizer=tokenizer,
                data_collator=data_collator,
                post_process_function=post_processing_function,
                compute_metrics=compute_metrics,
            ))

    # Training
    if training_args.do_train:
        checkpoint = None
        # if training_args.resume_from_checkpoint is not None:
        #     checkpoint = training_args.resume_from_checkpoint
        # elif last_checkpoint is not None:
        #     checkpoint = last_checkpoint
        if last_checkpoint is not None:
            checkpoint = last_checkpoint

        logger.info("num_train_epochs --- " +
                    str(training_args.num_train_epochs))
        logger.info("curr num_train_epochs --- " +
                    str(training_args_curr.num_train_epochs))
        train_result = trainer.train(resume_from_checkpoint=checkpoint)
        checkpoint = training_args.output_dir
        trainer.save_model()  # Saves the tokenizer too for easy upload
        logger.info("save model at " + training_args.output_dir)
        logger.info("trainer.state.global_step = %s",
                    trainer.state.global_step)
        # 归0
        trainer.state.global_step = 0
        trainer.save_state()
        torch.cuda.empty_cache()

        for i in range(data_args.div_subset):
            logger.info("******* 开始课程训练 *******")
            train_result = trainer_curr[i].train(
                resume_from_checkpoint=checkpoint)
            checkpoint = training_args.output_dir
            trainer_curr[i].save_model()
            logger.info("curr   save model at " + training_args.output_dir)

        metrics = train_result.metrics
        max_train_samples = (data_args.max_train_samples
                             if data_args.max_train_samples is not None else
                             len(train_dataset))
        metrics["train_samples"] = min(max_train_samples, len(train_dataset))

        # trainer.log_metrics("train", metrics)
        # trainer.save_metrics("train", metrics)
        # trainer.save_state()
        trainer_curr[data_args.div_subset - 1].log_metrics("train", metrics)
        trainer_curr[data_args.div_subset - 1].save_metrics("train", metrics)
        trainer_curr[data_args.div_subset - 1].save_state()
        torch.cuda.empty_cache()

    # Evaluation
    if training_args.do_eval:
        logger.info("*** Evaluate ***")
        # metrics = trainer.evaluate()
        metrics = trainer_curr[data_args.div_subset - 1].evaluate()

        max_eval_samples = data_args.max_eval_samples if data_args.max_eval_samples is not None else len(
            eval_dataset)
        metrics["eval_samples"] = min(max_eval_samples, len(eval_dataset))

        trainer_curr[data_args.div_subset - 1].log_metrics("eval", metrics)
        trainer_curr[data_args.div_subset - 1].save_metrics("eval", metrics)

    # Prediction
    if training_args.do_predict:
        logger.info("*** Predict ***")
        results = trainer.predict(predict_dataset, predict_examples)
        metrics = results.metrics

        max_predict_samples = (data_args.max_predict_samples
                               if data_args.max_predict_samples is not None
                               else len(predict_dataset))
        metrics["predict_samples"] = min(max_predict_samples,
                                         len(predict_dataset))

        trainer.log_metrics("predict", metrics)
        trainer.save_metrics("predict", metrics)

    if training_args.push_to_hub:
        trainer.push_to_hub()
Example #3
0
def main():
    # 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, TrainingArguments))
    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_qa_beam_search", model_args, data_args)

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

    # Log on each process the small summary:
    logger.warning(
        f"Process rank: {training_args.local_rank}, device: {training_args.device}, n_gpu: {training_args.n_gpu}"
        +
        f"distributed training: {bool(training_args.local_rank != -1)}, 16-bits training: {training_args.fp16}"
    )
    logger.info(f"Training/evaluation parameters {training_args}")

    # 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."
            )

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

    # Get the datasets: you can either provide your own CSV/JSON/TXT 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 column called 'text' or the first column if no column called
    # 'text' is found. You can easily tweak this behavior (see below).
    #
    # 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]
        if data_args.test_file is not None:
            data_files["test"] = data_args.test_file
            extension = data_args.test_file.split(".")[-1]
        raw_datasets = load_dataset(
            extension,
            data_files=data_files,
            field="data",
            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.

    # Load pretrained model and tokenizer
    #
    # Distributed training:
    # The .from_pretrained methods guarantee that only one local process can concurrently
    # download model & vocab.
    config = XLNetConfig.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 = XLNetTokenizerFast.from_pretrained(
        model_args.tokenizer_name
        if model_args.tokenizer_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,
    )
    model = XLNetForQuestionAnswering.from_pretrained(
        model_args.model_name_or_path,
        from_tf=bool(".ckpt" in 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,
    )

    # Preprocessing the datasets.
    # Preprocessing is slighlty different for training and evaluation.
    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:
        column_names = raw_datasets["test"].column_names
    question_column_name = "question" if "question" in column_names else column_names[
        0]
    context_column_name = "context" if "context" in column_names else column_names[
        1]
    answer_column_name = "answers" if "answers" in column_names else column_names[
        2]

    # Padding side determines if we do (question|context) or (context|question).
    pad_on_right = tokenizer.padding_side == "right"

    if data_args.max_seq_length > tokenizer.model_max_length:
        logger.warning(
            f"The max_seq_length passed ({data_args.max_seq_length}) is larger than the maximum length for the"
            f"model ({tokenizer.model_max_length}). Using max_seq_length={tokenizer.model_max_length}."
        )
    max_seq_length = min(data_args.max_seq_length, tokenizer.model_max_length)

    # Training preprocessing
    def prepare_train_features(examples):
        # Some of the questions have lots of whitespace on the left, which is not useful and will make the
        # truncation of the context fail (the tokenized question will take a lots of space). So we remove that
        # left whitespace
        examples[question_column_name] = [
            q.lstrip() for q in examples[question_column_name]
        ]

        # Tokenize our examples with truncation and maybe padding, but keep the overflows using a stride. This results
        # in one example possible giving several features when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.
        tokenized_examples = tokenizer(
            examples[
                question_column_name if pad_on_right else context_column_name],
            examples[
                context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            return_special_tokens_mask=True,
            return_token_type_ids=True,
            padding="max_length",
        )

        # Since one example might give us several features if it has a long context, we need a map from a feature to
        # its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")
        # The offset mappings will give us a map from token to character position in the original context. This will
        # help us compute the start_positions and end_positions.
        offset_mapping = tokenized_examples.pop("offset_mapping")
        # The special tokens will help us build the p_mask (which indicates the tokens that can't be in answers).
        special_tokens = tokenized_examples.pop("special_tokens_mask")

        # Let's label those examples!
        tokenized_examples["start_positions"] = []
        tokenized_examples["end_positions"] = []
        tokenized_examples["is_impossible"] = []
        tokenized_examples["cls_index"] = []
        tokenized_examples["p_mask"] = []

        for i, offsets in enumerate(offset_mapping):
            # We will label impossible answers with the index of the CLS token.
            input_ids = tokenized_examples["input_ids"][i]
            cls_index = input_ids.index(tokenizer.cls_token_id)
            tokenized_examples["cls_index"].append(cls_index)

            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            sequence_ids = tokenized_examples["token_type_ids"][i]
            for k, s in enumerate(special_tokens[i]):
                if s:
                    sequence_ids[k] = 3
            context_idx = 1 if pad_on_right else 0

            # Build the p_mask: non special tokens and context gets 0.0, the others get 1.0.
            # The cls token gets 1.0 too (for predictions of empty answers).
            tokenized_examples["p_mask"].append([
                0.0 if (not special_tokens[i][k] and s == context_idx)
                or k == cls_index else 1.0 for k, s in enumerate(sequence_ids)
            ])

            # One example can give several spans, this is the index of the example containing this span of text.
            sample_index = sample_mapping[i]
            answers = examples[answer_column_name][sample_index]
            # If no answers are given, set the cls_index as answer.
            if len(answers["answer_start"]) == 0:
                tokenized_examples["start_positions"].append(cls_index)
                tokenized_examples["end_positions"].append(cls_index)
                tokenized_examples["is_impossible"].append(1.0)
            else:
                # Start/end character index of the answer in the text.
                start_char = answers["answer_start"][0]
                end_char = start_char + len(answers["text"][0])

                # Start token index of the current span in the text.
                token_start_index = 0
                while sequence_ids[token_start_index] != context_idx:
                    token_start_index += 1

                # End token index of the current span in the text.
                token_end_index = len(input_ids) - 1
                while sequence_ids[token_end_index] != context_idx:
                    token_end_index -= 1
                # Detect if the answer is out of the span (in which case this feature is labeled with the CLS index).
                if not (offsets[token_start_index][0] <= start_char
                        and offsets[token_end_index][1] >= end_char):
                    tokenized_examples["start_positions"].append(cls_index)
                    tokenized_examples["end_positions"].append(cls_index)
                    tokenized_examples["is_impossible"].append(1.0)
                else:
                    # Otherwise move the token_start_index and token_end_index to the two ends of the answer.
                    # Note: we could go after the last offset if the answer is the last word (edge case).
                    while token_start_index < len(offsets) and offsets[
                            token_start_index][0] <= start_char:
                        token_start_index += 1
                    tokenized_examples["start_positions"].append(
                        token_start_index - 1)
                    while offsets[token_end_index][1] >= end_char:
                        token_end_index -= 1
                    tokenized_examples["end_positions"].append(
                        token_end_index + 1)
                    tokenized_examples["is_impossible"].append(0.0)

        return tokenized_examples

    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:
            # Select samples from Dataset, This will help to decrease processing time
            max_train_samples = min(len(train_dataset),
                                    data_args.max_train_samples)
            train_dataset = train_dataset.select(range(max_train_samples))
        # Create Training Features
        with training_args.main_process_first(
                desc="train dataset map pre-processing"):
            train_dataset = train_dataset.map(
                prepare_train_features,
                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",
            )
        if data_args.max_train_samples is not None:
            # Select samples from dataset again since Feature Creation might increase number of features
            max_train_samples = min(len(train_dataset),
                                    data_args.max_train_samples)
            train_dataset = train_dataset.select(range(max_train_samples))

    # Validation preprocessing
    def prepare_validation_features(examples):
        # Tokenize our examples with truncation and maybe padding, but keep the overflows using a stride. This results
        # in one example possible giving several features when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.
        tokenized_examples = tokenizer(
            examples[
                question_column_name if pad_on_right else context_column_name],
            examples[
                context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            return_special_tokens_mask=True,
            return_token_type_ids=True,
            padding="max_length",
        )

        # Since one example might give us several features if it has a long context, we need a map from a feature to
        # its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")

        # The special tokens will help us build the p_mask (which indicates the tokens that can't be in answers).
        special_tokens = tokenized_examples.pop("special_tokens_mask")

        # For evaluation, we will need to convert our predictions to substrings of the context, so we keep the
        # corresponding example_id and we will store the offset mappings.
        tokenized_examples["example_id"] = []

        # We still provide the index of the CLS token and the p_mask to the model, but not the is_impossible label.
        tokenized_examples["cls_index"] = []
        tokenized_examples["p_mask"] = []

        for i, input_ids in enumerate(tokenized_examples["input_ids"]):
            # Find the CLS token in the input ids.
            cls_index = input_ids.index(tokenizer.cls_token_id)
            tokenized_examples["cls_index"].append(cls_index)

            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            sequence_ids = tokenized_examples["token_type_ids"][i]
            for k, s in enumerate(special_tokens[i]):
                if s:
                    sequence_ids[k] = 3
            context_idx = 1 if pad_on_right else 0

            # Build the p_mask: non special tokens and context gets 0.0, the others 1.0.
            tokenized_examples["p_mask"].append([
                0.0 if (not special_tokens[i][k] and s == context_idx)
                or k == cls_index else 1.0 for k, s in enumerate(sequence_ids)
            ])

            # One example can give several spans, this is the index of the example containing this span of text.
            sample_index = sample_mapping[i]
            tokenized_examples["example_id"].append(
                examples["id"][sample_index])

            # Set to None the offset_mapping that are not part of the context so it's easy to determine if a token
            # position is part of the context or not.
            tokenized_examples["offset_mapping"][i] = [
                (o if sequence_ids[k] == context_idx else None)
                for k, o in enumerate(tokenized_examples["offset_mapping"][i])
            ]

        return tokenized_examples

    if training_args.do_eval:
        if "validation" not in raw_datasets:
            raise ValueError("--do_eval requires a validation dataset")
        eval_examples = raw_datasets["validation"]
        if data_args.max_eval_samples is not None:
            # Selecting Eval Samples from Dataset
            max_eval_samples = min(len(eval_examples),
                                   data_args.max_eval_samples)
            eval_examples = eval_examples.select(range(max_eval_samples))
        # Create Features from Eval Dataset
        with training_args.main_process_first(
                desc="validation dataset map pre-processing"):
            eval_dataset = eval_examples.map(
                prepare_validation_features,
                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",
            )
        if data_args.max_eval_samples is not None:
            # Selecting Samples from Dataset again since Feature Creation might increase samples size
            max_eval_samples = min(len(eval_dataset),
                                   data_args.max_eval_samples)
            eval_dataset = eval_dataset.select(range(max_eval_samples))

    if training_args.do_predict:
        if "test" not in raw_datasets:
            raise ValueError("--do_predict requires a test dataset")
        predict_examples = raw_datasets["test"]
        if data_args.max_predict_samples is not None:
            # We will select sample from whole data
            predict_examples = predict_examples.select(
                range(data_args.max_predict_samples))
        # Test Feature Creation
        with training_args.main_process_first(
                desc="prediction dataset map pre-processing"):
            predict_dataset = predict_examples.map(
                prepare_validation_features,
                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 prediction dataset",
            )
        if data_args.max_predict_samples is not None:
            # During Feature creation dataset samples might increase, we will select required samples again
            max_predict_samples = min(len(predict_dataset),
                                      data_args.max_predict_samples)
            predict_dataset = predict_dataset.select(
                range(max_predict_samples))

    # Data collator
    # We have already padded to max length if the corresponding flag is True, otherwise we need to pad in the data
    # collator.
    data_collator = (default_data_collator if data_args.pad_to_max_length else
                     DataCollatorWithPadding(
                         tokenizer,
                         pad_to_multiple_of=8 if training_args.fp16 else None))

    # Post-processing:
    def post_processing_function(examples,
                                 features,
                                 predictions,
                                 stage="eval"):
        # Post-processing: we match the start logits and end logits to answers in the original context.
        predictions, scores_diff_json = postprocess_qa_predictions_with_beam_search(
            examples=examples,
            features=features,
            predictions=predictions,
            version_2_with_negative=data_args.version_2_with_negative,
            n_best_size=data_args.n_best_size,
            max_answer_length=data_args.max_answer_length,
            start_n_top=model.config.start_n_top,
            end_n_top=model.config.end_n_top,
            output_dir=training_args.output_dir,
            log_level=log_level,
            prefix=stage,
        )
        # Format the result to the format the metric expects.
        if data_args.version_2_with_negative:
            formatted_predictions = [{
                "id":
                k,
                "prediction_text":
                v,
                "no_answer_probability":
                scores_diff_json[k]
            } for k, v in predictions.items()]
        else:
            formatted_predictions = [{
                "id": k,
                "prediction_text": v
            } for k, v in predictions.items()]

        references = [{
            "id": ex["id"],
            "answers": ex[answer_column_name]
        } for ex in examples]
        return EvalPrediction(predictions=formatted_predictions,
                              label_ids=references)

    metric = evaluate.load(
        "squad_v2" if data_args.version_2_with_negative else "squad")

    def compute_metrics(p: EvalPrediction):
        return metric.compute(predictions=p.predictions,
                              references=p.label_ids)

    # Initialize our Trainer
    trainer = QuestionAnsweringTrainer(
        model=model,
        args=training_args,
        train_dataset=train_dataset if training_args.do_train else None,
        eval_dataset=eval_dataset if training_args.do_eval else None,
        eval_examples=eval_examples if training_args.do_eval else None,
        tokenizer=tokenizer,
        data_collator=data_collator,
        post_process_function=post_processing_function,
        compute_metrics=compute_metrics,
    )

    # Training
    if training_args.do_train:
        checkpoint = None
        if training_args.resume_from_checkpoint is not None:
            checkpoint = training_args.resume_from_checkpoint
        elif last_checkpoint is not None:
            checkpoint = last_checkpoint
        train_result = trainer.train(resume_from_checkpoint=checkpoint)
        trainer.save_model()  # Saves the tokenizer too for easy upload

        metrics = train_result.metrics

        max_train_samples = (data_args.max_train_samples
                             if data_args.max_train_samples is not None else
                             len(train_dataset))
        metrics["train_samples"] = min(max_train_samples, len(train_dataset))

        trainer.log_metrics("train", metrics)
        trainer.save_metrics("train", metrics)
        trainer.save_state()

    # Evaluation
    if training_args.do_eval:
        logger.info("*** Evaluate ***")
        metrics = trainer.evaluate()

        max_eval_samples = data_args.max_eval_samples if data_args.max_eval_samples is not None else len(
            eval_dataset)
        metrics["eval_samples"] = min(max_eval_samples, len(eval_dataset))

        trainer.log_metrics("eval", metrics)
        trainer.save_metrics("eval", metrics)

    # Prediction
    if training_args.do_predict:
        logger.info("*** Predict ***")
        results = trainer.predict(predict_dataset, predict_examples)
        metrics = results.metrics

        max_predict_samples = (data_args.max_predict_samples
                               if data_args.max_predict_samples is not None
                               else len(predict_dataset))
        metrics["predict_samples"] = min(max_predict_samples,
                                         len(predict_dataset))

        trainer.log_metrics("predict", metrics)
        trainer.save_metrics("predict", metrics)

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

    if training_args.push_to_hub:
        trainer.push_to_hub(**kwargs)
    else:
        trainer.create_model_card(**kwargs)
Example #4
0
def run_mrc(data_args, training_args, model_args, datasets, tokenizer, model):
    # Preprocessing the datasets.
    # Preprocessing is slighlty different for training and evaluation.
    if training_args.do_train:
        column_names = datasets["train"].column_names
    else:
        column_names = datasets["validation"].column_names

    question_column_name = "question" if "question" in column_names else column_names[
        0]
    context_column_name = "context" if "context" in column_names else column_names[
        1]
    answer_column_name = "answers" if "answers" in column_names else column_names[
        2]

    # Padding side determines if we do (question|context) or (context|question).
    pad_on_right = tokenizer.padding_side == "right"

    # check if there is an error
    last_checkpoint, max_seq_length = check_no_error(training_args, data_args,
                                                     tokenizer, datasets)

    # Training preprocessing
    def prepare_train_features(examples):
        # Tokenize our examples with truncation and maybe padding, but keep the overflows using a stride. This results
        # in one example possible giving several features when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.
        tokenized_examples = tokenizer(
            examples[
                question_column_name if pad_on_right else context_column_name],
            examples[
                context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            padding="max_length" if data_args.pad_to_max_length else False,
        )

        # Since one example might give us several features if it has a long context, we need a map from a feature to
        # its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")
        # The offset mappings will give us a map from token to character position in the original context. This will
        # help us compute the start_positions and end_positions.
        offset_mapping = tokenized_examples.pop("offset_mapping")

        # Let's label those examples!
        tokenized_examples["start_positions"] = []
        tokenized_examples["end_positions"] = []

        for i, offsets in enumerate(offset_mapping):
            # We will label impossible answers with the index of the CLS token.
            input_ids = tokenized_examples["input_ids"][i]
            cls_index = input_ids.index(tokenizer.cls_token_id)

            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            sequence_ids = tokenized_examples.sequence_ids(i)

            # One example can give several spans, this is the index of the example containing this span of text.
            sample_index = sample_mapping[i]
            answers = examples[answer_column_name][sample_index]
            # print(answers)
            # If no answers are given, set the cls_index as answer.
            if len(answers["answer_start"]) == 0:
                tokenized_examples["start_positions"].append(cls_index)
                tokenized_examples["end_positions"].append(cls_index)
            else:
                # Start/end character index of the answer in the text.
                start_char = answers["answer_start"][0]
                end_char = start_char + len(answers["text"][0])

                # Start token index of the current span in the text.
                token_start_index = 0
                while sequence_ids[token_start_index] != (1 if pad_on_right
                                                          else 0):
                    token_start_index += 1

                # End token index of the current span in the text.
                token_end_index = len(input_ids) - 1
                while sequence_ids[token_end_index] != (1 if pad_on_right else
                                                        0):
                    token_end_index -= 1

                # Detect if the answer is out of the span (in which case this feature is labeled with the CLS index).
                if not (offsets[token_start_index][0] <= start_char
                        and offsets[token_end_index][1] >= end_char):
                    tokenized_examples["start_positions"].append(cls_index)
                    tokenized_examples["end_positions"].append(cls_index)
                else:
                    # Otherwise move the token_start_index and token_end_index to the two ends of the answer.
                    # Note: we could go after the last offset if the answer is the last word (edge case).
                    while (token_start_index < len(offsets)
                           and offsets[token_start_index][0] <= start_char):
                        token_start_index += 1
                    tokenized_examples["start_positions"].append(
                        token_start_index - 1)
                    while offsets[token_end_index][1] >= end_char:
                        token_end_index -= 1
                    tokenized_examples["end_positions"].append(
                        token_end_index + 1)

        return tokenized_examples

    if training_args.do_train:
        if "train" not in datasets:
            raise ValueError("--do_train requires a train dataset")
        train_dataset = datasets["train"]

        # Create train feature from dataset
        train_dataset = train_dataset.map(
            prepare_train_features,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            remove_columns=column_names,
            load_from_cache_file=not data_args.overwrite_cache,
        )

    # Validation preprocessing
    def prepare_validation_features(examples):
        # Tokenize our examples with truncation and maybe padding, but keep the overflows using a stride. This results
        # in one example possible giving several features when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.
        tokenized_examples = tokenizer(
            examples[
                question_column_name if pad_on_right else context_column_name],
            examples[
                context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            padding="max_length" if data_args.pad_to_max_length else False,
        )

        # Since one example might give us several features if it has a long context, we need a map from a feature to
        # its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")

        # For evaluation, we will need to convert our predictions to substrings of the context, so we keep the
        # corresponding example_id and we will store the offset mappings.
        tokenized_examples["example_id"] = []

        for i in range(len(tokenized_examples["input_ids"])):
            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            sequence_ids = tokenized_examples.sequence_ids(i)
            context_index = 1 if pad_on_right else 0

            # One example can give several spans, this is the index of the example containing this span of text.
            sample_index = sample_mapping[i]
            tokenized_examples["example_id"].append(
                examples["id"][sample_index])

            # Set to None the offset_mapping that are not part of the context so it's easy to determine if a token
            # position is part of the context or not.
            tokenized_examples["offset_mapping"][i] = [
                (o if sequence_ids[k] == context_index else None)
                for k, o in enumerate(tokenized_examples["offset_mapping"][i])
            ]
        return tokenized_examples

    if training_args.do_eval:
        eval_dataset = datasets["validation"]

        # Validation Feature Creation
        eval_dataset = eval_dataset.map(
            prepare_validation_features,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            remove_columns=column_names,
            load_from_cache_file=not data_args.overwrite_cache,
        )

    # Data collator
    # We have already padded to max length if the corresponding flag is True, otherwise we need to pad in the data collator.
    data_collator = (DataCollatorWithPadding(
        tokenizer, pad_to_multiple_of=8 if training_args.fp16 else None))

    # Post-processing:
    def post_processing_function(examples, features, predictions,
                                 training_args):
        # Post-processing: we match the start logits and end logits to answers in the original context.
        predictions = postprocess_qa_predictions(
            examples=examples,
            features=features,
            predictions=predictions,
            max_answer_length=data_args.max_answer_length,
            output_dir=training_args.output_dir,
        )
        # Format the result to the format the metric expects.
        formatted_predictions = [{
            "id": k,
            "prediction_text": v
        } for k, v in predictions.items()]
        if training_args.do_predict:
            return formatted_predictions

        elif training_args.do_eval:
            references = [{
                "id": ex["id"],
                "answers": ex[answer_column_name]
            } for ex in datasets["validation"]]
            return EvalPrediction(predictions=formatted_predictions,
                                  label_ids=references)

    metric = load_metric("squad")

    def compute_metrics(p: EvalPrediction):
        return metric.compute(predictions=p.predictions,
                              references=p.label_ids)

    # Initialize our Trainer
    trainer = QuestionAnsweringTrainer(
        model=model,
        args=training_args,
        train_dataset=train_dataset if training_args.do_train else None,
        eval_dataset=eval_dataset if training_args.do_eval else None,
        eval_examples=datasets["validation"]
        if training_args.do_eval else None,
        tokenizer=tokenizer,
        data_collator=data_collator,
        post_process_function=post_processing_function,
        compute_metrics=compute_metrics,
    )

    # Training
    if training_args.do_train:
        if last_checkpoint is not None:
            checkpoint = last_checkpoint
        elif os.path.isdir(model_args.model_name_or_path):
            checkpoint = model_args.model_name_or_path
        else:
            checkpoint = None
        train_result = trainer.train(resume_from_checkpoint=checkpoint)
        trainer.save_model()  # Saves the tokenizer too for easy upload

        metrics = train_result.metrics
        metrics["train_samples"] = len(train_dataset)

        trainer.log_metrics("train", metrics)
        trainer.save_metrics("train", metrics)
        trainer.save_state()

        output_train_file = os.path.join(training_args.output_dir,
                                         "train_results.txt")

        with open(output_train_file, "w") as writer:
            logger.info("***** Train results *****")
            for key, value in sorted(train_result.metrics.items()):
                logger.info(f"  {key} = {value}")
                writer.write(f"{key} = {value}\n")

        # Need to save the state, since Trainer.save_model saves only the tokenizer with the model
        trainer.state.save_to_json(
            os.path.join(training_args.output_dir, "trainer_state.json"))

    # Evaluation
    if training_args.do_eval:
        logger.info("*** Evaluate ***")
        metrics = trainer.evaluate()

        metrics["eval_samples"] = len(eval_dataset)

        trainer.log_metrics("eval", metrics)
        trainer.save_metrics("eval", metrics)
Example #5
0
def main():
    model_args, data_args, training_args = __parse_args()
    __setup_logging(training_args.should_log)
    __log_summary(training_args)

    last_checkpoint = __get_last_checkpoint(training_args)

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

    datasets = __get_datasets(data_args, model_args.cache_dir)
    tokenizer, model = __get_model(model_args)

    # Preprocessing the datasets.
    # Preprocessing is slighlty different for training and evaluation.
    column_names = __get_dataset_column_names(training_args, datasets)
    q_col_name, c_col_name, a_col_name = __get_qcas(column_names)

    # Padding side determines if we do (question|context) or (context|question).
    pad_on_right = tokenizer.padding_side == "right"

    max_seq_length = __get_max_seq_length(data_args, tokenizer)

    if training_args.do_train:
        train_dataset = __preprocess_train_dataset(
            datasets,
            tokenizer,
            data_args,
            q_col_name,
            c_col_name,
            a_col_name,
            column_names,
            pad_on_right,
            max_seq_length,
        )

    # Validation preprocessing
    def prepare_validation_features(examples):
        # Tokenize our examples with truncation and maybe padding, but keep the overflows
        # using a stride. This results in one example possible giving several features
        # when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.
        tokenized_examples = tokenizer(
            examples[q_col_name if pad_on_right else c_col_name],
            examples[c_col_name if pad_on_right else q_col_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            padding="max_length" if data_args.pad_to_max_length else False,
        )

        # Since one example might give us several features if it has a long context,
        # we need a map from a feature to its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")

        # For evaluation, we will need to convert our predictions to substrings of the context,
        # so we keep the corresponding example_id and we will store the offset mappings.
        tokenized_examples["example_id"] = []

        for i in range(len(tokenized_examples["input_ids"])):
            # Grab the sequence corresponding to that example (to know what is the context
            # and what is the question).
            sequence_ids = tokenized_examples.sequence_ids(i)
            context_index = 1 if pad_on_right else 0

            # One example can give several spans, this is the index of the example
            # containing this span of text.
            sample_index = sample_mapping[i]
            tokenized_examples["example_id"].append(
                examples["id"][sample_index])

            # Set to None the offset_mapping that are not part of the context
            # so it's easy to determine if a token position is part of the context or not.
            tokenized_examples["offset_mapping"][i] = [
                (o if sequence_ids[k] == context_index else None)
                for k, o in enumerate(tokenized_examples["offset_mapping"][i])
            ]

        return tokenized_examples

    if training_args.do_eval:
        if "validation" not in datasets:
            raise ValueError("--do_eval requires a validation dataset")
        eval_examples = datasets["validation"]
        if data_args.max_eval_samples is not None:
            # We will select sample from whole data
            eval_examples = eval_examples.select(
                range(data_args.max_eval_samples))
        # Validation Feature Creation
        eval_dataset = eval_examples.map(
            prepare_validation_features,
            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",
        )
        if data_args.max_eval_samples is not None:
            # During Feature creation dataset samples might increase,
            # we will select required samples again
            eval_dataset = eval_dataset.select(
                range(data_args.max_eval_samples))

    if training_args.do_predict:
        if "test" not in datasets:
            raise ValueError("--do_predict requires a test dataset")
        predict_examples = datasets["test"]
        if data_args.max_predict_samples is not None:
            # We will select sample from whole data
            predict_examples = predict_examples.select(
                range(data_args.max_predict_samples))
        # Predict Feature Creation
        predict_dataset = predict_examples.map(
            prepare_validation_features,
            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 prediction dataset",
        )
        if data_args.max_predict_samples is not None:
            # During Feature creation dataset samples might increase,
            # we will select required samples again
            predict_dataset = predict_dataset.select(
                range(data_args.max_predict_samples))

    # Data collator
    # We have already padded to max length if the corresponding flag is True,
    # otherwise we need to pad in the data collator.
    data_collator = (default_data_collator if data_args.pad_to_max_length else
                     DataCollatorWithPadding(
                         tokenizer,
                         pad_to_multiple_of=8 if training_args.fp16 else None))

    # Post-processing:
    def post_processing_function(examples,
                                 features,
                                 predictions,
                                 stage="eval"):
        # Post-processing: we match the start logits and end logits
        # to answers in the original context.
        predictions = postprocess_qa_predictions(
            examples=examples,
            features=features,
            predictions=predictions,
            version_2_with_negative=data_args.version_2_with_negative,
            n_best_size=data_args.n_best_size,
            max_answer_length=data_args.max_answer_length,
            null_score_diff_threshold=data_args.null_score_diff_threshold,
            output_dir=training_args.output_dir,
            is_world_process_zero=trainer.is_world_process_zero(),
            prefix=stage,
        )
        # Format the result to the format the metric expects.
        if data_args.version_2_with_negative:
            formatted_predictions = [{
                "id": k,
                "prediction_text": v,
                "no_answer_probability": 0.0
            } for k, v in predictions.items()]
        else:
            formatted_predictions = [{
                "id": k,
                "prediction_text": v
            } for k, v in predictions.items()]

        references = [{
            "id": ex["id"],
            "answers": ex[a_col_name]
        } for ex in examples]
        return EvalPrediction(predictions=formatted_predictions,
                              label_ids=references)

    metric = load_metric(
        "squad_v2" if data_args.version_2_with_negative else "squad")

    def compute_metrics(p: EvalPrediction):
        return metric.compute(predictions=p.predictions,
                              references=p.label_ids)

    # Initialize our Trainer
    trainer = QuestionAnsweringTrainer(
        model=model,
        args=training_args,
        train_dataset=train_dataset if training_args.do_train else None,
        eval_dataset=eval_dataset if training_args.do_eval else None,
        eval_examples=eval_examples if training_args.do_eval else None,
        tokenizer=tokenizer,
        data_collator=data_collator,
        post_process_function=post_processing_function,
        compute_metrics=compute_metrics,
    )

    # Training
    if training_args.do_train:
        checkpoint = None
        if training_args.resume_from_checkpoint is not None:
            checkpoint = training_args.resume_from_checkpoint
        elif last_checkpoint is not None:
            checkpoint = last_checkpoint
        train_result = trainer.train(resume_from_checkpoint=checkpoint)
        trainer.save_model()  # Saves the tokenizer too for easy upload

        metrics = train_result.metrics
        max_train_samples = (data_args.max_train_samples
                             if data_args.max_train_samples is not None else
                             len(train_dataset))
        metrics["train_samples"] = min(max_train_samples, len(train_dataset))

        trainer.log_metrics("train", metrics)
        trainer.save_metrics("train", metrics)
        trainer.save_state()

    # Evaluation
    if training_args.do_eval:
        logger.info("*** Evaluate ***")
        metrics = trainer.evaluate()

        max_eval_samples = (data_args.max_eval_samples
                            if data_args.max_eval_samples is not None else
                            len(eval_dataset))
        metrics["eval_samples"] = min(max_eval_samples, len(eval_dataset))

        trainer.log_metrics("eval", metrics)
        trainer.save_metrics("eval", metrics)

    # Prediction
    if training_args.do_predict:
        logger.info("*** Predict ***")
        results = trainer.predict(predict_dataset, predict_examples)
        metrics = results.metrics

        max_predict_samples = (data_args.max_predict_samples
                               if data_args.max_predict_samples is not None
                               else len(predict_dataset))
        metrics["predict_samples"] = min(max_predict_samples,
                                         len(predict_dataset))

        trainer.log_metrics("predict", metrics)
        trainer.save_metrics("predict", metrics)

    if training_args.push_to_hub:
        kwargs = {
            "finetuned_from": model_args.model_name_or_path,
            "tasks": "question-answering",
        }
        if data_args.dataset_name is not None:
            kwargs["dataset_tags"] = data_args.dataset_name
            if data_args.dataset_config_name is not None:
                kwargs["dataset_args"] = data_args.dataset_config_name
                kwargs[
                    "dataset"] = f"{data_args.dataset_name} {data_args.dataset_config_name}"
            else:
                kwargs["dataset"] = data_args.dataset_name

        trainer.push_to_hub(**kwargs)
Example #6
0
def main():
    ### Dataset processing classes in main due to hugging face custom dataset map
    def prepare_train_features(examples):
        # Tokenize our examples with truncation and maybe padding, but keep the overflows using a stride. This results
        # in one example possible giving several features when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.
        tokenized_examples = tokenizer(
            examples[
                question_column_name if pad_on_right else context_column_name],
            examples[
                context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=data_args.max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            padding="max_length" if data_args.pad_to_max_length else False,
        )

        # Since one example might give us several features if it has a long context, we need a map from a feature to
        # its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")
        # The offset mappings will give us a map from token to character position in the original context. This will
        # help us compute the start_positions and end_positions.
        offset_mapping = tokenized_examples.pop("offset_mapping")

        # Let's label those examples!
        tokenized_examples["start_positions"] = []
        tokenized_examples["end_positions"] = []

        for i, offsets in enumerate(offset_mapping):
            # We will label impossible answers with the index of the CLS token.
            input_ids = tokenized_examples["input_ids"][i]
            cls_index = input_ids.index(tokenizer.cls_token_id)

            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            sequence_ids = tokenized_examples.sequence_ids(i)

            # One example can give several spans, this is the index of the example containing this span of text.
            sample_index = sample_mapping[i]
            answers = examples[answer_column_name][sample_index]
            # If no answers are given, set the cls_index as answer.
            if len(answers["answer_start"]) == 0:
                tokenized_examples["start_positions"].append(cls_index)
                tokenized_examples["end_positions"].append(cls_index)
            else:
                # Start/end character index of the answer in the text.
                start_char = answers["answer_start"][0]
                end_char = start_char + len(answers["text"][0])

                # Start token index of the current span in the text.
                token_start_index = 0
                while sequence_ids[token_start_index] != (1 if pad_on_right
                                                          else 0):
                    token_start_index += 1

                # End token index of the current span in the text.
                token_end_index = len(input_ids) - 1
                while sequence_ids[token_end_index] != (1 if pad_on_right else
                                                        0):
                    token_end_index -= 1

                # Detect if the answer is out of the span (in which case this feature is labeled with the CLS index).
                if not (offsets[token_start_index][0] <= start_char
                        and offsets[token_end_index][1] >= end_char):
                    tokenized_examples["start_positions"].append(cls_index)
                    tokenized_examples["end_positions"].append(cls_index)
                else:
                    # Otherwise move the token_start_index and token_end_index to the two ends of the answer.
                    # Note: we could go after the last offset if the answer is the last word (edge case).
                    while (token_start_index < len(offsets)
                           and offsets[token_start_index][0] <= start_char):
                        token_start_index += 1
                    tokenized_examples["start_positions"].append(
                        token_start_index - 1)
                    while offsets[token_end_index][1] >= end_char:
                        token_end_index -= 1
                    tokenized_examples["end_positions"].append(
                        token_end_index + 1)
        return tokenized_examples

    def compute_metrics(p: EvalPrediction):
        return metric.compute(predictions=p.predictions,
                              references=p.label_ids)

    # Post-processing:
    def post_processing_function(examples, features, predictions):
        predictions = postprocess_qa_predictions(
            examples=examples,
            features=features,
            predictions=predictions,
            version_2_with_negative=data_args.version_2_with_negative,
            n_best_size=data_args.n_best_size,
            max_answer_length=data_args.max_answer_length,
            null_score_diff_threshold=data_args.null_score_diff_threshold,
            output_dir=training_args.output_dir,
            is_world_process_zero=trainer.is_world_process_zero(),
        )
        if data_args.version_2_with_negative:
            formatted_predictions = [{
                "id": k,
                "prediction_text": v,
                "no_answer_probability": 0.0
            } for k, v in predictions.items()]
        else:
            formatted_predictions = [{
                "id": k,
                "prediction_text": v
            } for k, v in predictions.items()]
        references = [{
            "id": ex["id"],
            "answers": ex[answer_column_name]
        } for ex in datasets["validation"]]
        return EvalPrediction(predictions=formatted_predictions,
                              label_ids=references)

    # Validation preprocessing
    def prepare_validation_features(examples):
        # Tokenize our examples with truncation and maybe padding, but keep the overflows using a stride. This results
        # in one example possible giving several features when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.
        tokenized_examples = tokenizer(
            examples[
                question_column_name if pad_on_right else context_column_name],
            examples[
                context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=data_args.max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            padding="max_length" if data_args.pad_to_max_length else False,
        )

        # Since one example might give us several features if it has a long context, we need a map from a feature to
        # its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")

        # For evaluation, we will need to convert our predictions to substrings of the context, so we keep the
        # corresponding example_id and we will store the offset mappings.
        tokenized_examples["example_id"] = []

        for i in range(len(tokenized_examples["input_ids"])):
            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            sequence_ids = tokenized_examples.sequence_ids(i)
            context_index = 1 if pad_on_right else 0

            # One example can give several spans, this is the index of the example containing this span of text.
            sample_index = sample_mapping[i]
            tokenized_examples["example_id"].append(
                examples["id"][sample_index])

            # Set to None the offset_mapping that are not part of the context so it's easy to determine if a token
            # position is part of the context or not.
            tokenized_examples["offset_mapping"][i] = [
                (o if sequence_ids[k] == context_index else None)
                for k, o in enumerate(tokenized_examples["offset_mapping"][i])
            ]

        return tokenized_examples

    transformers.utils.logging.set_verbosity_info()
    parser = HfArgumentParser(
        (ModelArguments, DataTrainingArguments, TrainingArguments))
    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(
        )
    if (os.path.exists(training_args.output_dir)
            and os.listdir(training_args.output_dir) and training_args.do_train
            and not training_args.overwrite_output_dir):
        raise ValueError(
            f"Output directory ({training_args.output_dir}) already exists and is not empty."
            "Use --overwrite_output_dir to overcome.")

    logging.basicConfig(
        format="%(asctime)s - %(levelname)s - %(name)s -   %(message)s",
        datefmt="%m/%d/%Y %H:%M:%S",
    )
    logger.setLevel(logging.INFO if is_main_process(training_args.local_rank
                                                    ) else logging.WARN)

    logger.warning(
        f"Process rank: {training_args.local_rank}, device: {training_args.device}, n_gpu: {training_args.n_gpu}"
        +
        f"distributed training: {bool(training_args.local_rank != -1)}, 16-bits training: {training_args.fp16}"
    )

    if is_main_process(training_args.local_rank):
        transformers.utils.logging.set_verbosity_info()
    logger.info("Training/evaluation parameters %s", training_args)

    set_seed(training_args.seed)
    if data_args.dataset_name is not None:
        datasets = load_dataset(data_args.dataset_name,
                                data_args.dataset_config_name)
    else:
        data_files = {}
        if data_args.train_file is not None:
            data_files["train"] = data_args.train_file
        if data_args.validation_file is not None:
            data_files["validation"] = data_args.validation_file
        extension = data_args.train_file.split(".")[-1]
        datasets = load_dataset(extension, data_files=data_files, field="data")
    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,
    )
    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=True,
    )
    model = AutoModelForQuestionAnswering.from_pretrained(
        model_args.model_name_or_path,
        from_tf=bool(".ckpt" in model_args.model_name_or_path),
        config=config,
        cache_dir=model_args.cache_dir,
    )

    if data_args.layers_to_keep > 0:
        logger.info("Keeping %s model layers", data_args.layers_to_keep)
        model = drop_layers(model, data_args.layers_to_keep)

    model_parameters = filter(lambda p: p.requires_grad, model.parameters())
    params = sum([np.prod(p.size()) for p in model_parameters])
    logger.info("Model has %s parameters", params)
    # Tokenizer check: this script requires a fast tokenizer.
    if not isinstance(tokenizer, PreTrainedTokenizerFast):
        raise ValueError(
            "This example script only works for models that have a fast tokenizer. Checkout the big table of models "
            "at https://huggingface.co/transformers/index.html#bigtable to find the model types that meet this "
            "requirement")

    if training_args.do_train:
        column_names = datasets["train"].column_names
    else:
        column_names = datasets["validation"].column_names
    question_column_name = "question" if "question" in column_names else column_names[
        0]
    context_column_name = "context" if "context" in column_names else column_names[
        1]
    answer_column_name = "answers" if "answers" in column_names else column_names[
        2]
    pad_on_right = tokenizer.padding_side == "right"

    if training_args.do_train:
        train_dataset = datasets["train"].map(
            prepare_train_features,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            remove_columns=column_names,
            load_from_cache_file=not data_args.overwrite_cache,
        )

    if training_args.do_eval:
        validation_dataset = datasets["validation"].map(
            prepare_validation_features,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            remove_columns=column_names,
            load_from_cache_file=not data_args.overwrite_cache,
        )

    data_collator = (default_data_collator if data_args.pad_to_max_length else
                     DataCollatorWithPadding(tokenizer))

    current_dir = os.path.sep.join(
        os.path.join(__file__).split(os.path.sep)[:-1])
    metric = load_metric(
        os.path.join(current_dir, "squad_v2_local") if data_args.
        version_2_with_negative else "squad")

    ####################################################################################
    # Start SparseML Integration
    ####################################################################################
    optim = load_optimizer(model, TrainingArguments)
    steps_per_epoch = math.ceil(
        len(datasets["train"]) /
        (training_args.per_device_train_batch_size * training_args._n_gpu))
    manager = ScheduledModifierManager.from_yaml(data_args.nm_prune_config)
    training_args.num_train_epochs = float(manager.modifiers[0].end_epoch)
    optim = ScheduledOptimizer(optim,
                               model,
                               manager,
                               steps_per_epoch=steps_per_epoch,
                               loggers=None)
    ####################################################################################
    # End SparseML Integration
    ####################################################################################
    # Initialize our Trainer
    trainer = QuestionAnsweringTrainer(
        model=model,
        args=training_args,
        train_dataset=train_dataset if training_args.do_train else None,
        eval_dataset=validation_dataset if training_args.do_eval else None,
        eval_examples=datasets["validation"]
        if training_args.do_eval else None,
        tokenizer=tokenizer,
        data_collator=data_collator,
        post_process_function=post_processing_function,
        compute_metrics=compute_metrics,
        optimizers=(optim, None),
    )

    # Training
    if training_args.do_train:
        trainer.train(model_path=model_args.model_name_or_path if os.path.
                      isdir(model_args.model_name_or_path) else None)
        trainer.save_model()  # Saves the tokenizer too for easy upload

    # Evaluation
    results = {}
    if training_args.do_eval:
        logger.info("*** Evaluate ***")
        results = trainer.evaluate()

        output_eval_file = os.path.join(training_args.output_dir,
                                        "eval_results.txt")
        if trainer.is_world_process_zero():
            with open(output_eval_file, "w") as writer:
                logger.info("***** Eval results *****")
                for key, value in results.items():
                    logger.info(f"  {key} = {value}")
                    writer.write(f"{key} = {value}\n")

    ####################################################################################
    # Start SparseML Integration
    ####################################################################################
    if data_args.do_onnx_export:
        logger.info("*** Export to ONNX ***")
        print("Exporting onnx model")
        os.environ["TOKENIZERS_PARALLELISM"] = "false"
        exporter = ModuleExporter(model, output_dir='onnx-export')
        sample_batch = convert_example_to_features(
            datasets["validation"][0],
            tokenizer,
            data_args.max_seq_length,
            data_args.doc_stride,
            data_args.max_query_length,
        )
        exporter.export_onnx(sample_batch=sample_batch)
Example #7
0
def run_mrc(data_args, training_args, model_args, datasets, tokenizer, model):
    # wandb 사용할 경우
    # wandb.login()    

    question_column_name = "question" if "question" in column_names else column_names[0]
    context_column_name = "context" if "context" in column_names else column_names[1]
    answer_column_name = "answers" if "answers" in column_names else column_names[2]

    # Padding side determines if we do (question|context) or (context|question).
    pad_on_right = tokenizer.padding_side == "right"

    # check if there is an error
    last_checkpoint, max_seq_length = check_no_error(training_args, data_args, tokenizer, datasets)

    # train 데이터 가공 과정
    def prepare_train_features(examples):
        # 토크나이징 + 정답 start, end 토큰 위치 모두 겸비한 input data 만들기!

        tokenized_examples = tokenizer(
            examples[question_column_name if pad_on_right else context_column_name],
            examples[context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True, 
            padding="max_length" if data_args.pad_to_max_length else False,
        )

        # truncation으로 분리된 data가 원래 어느 context에 소속되었는지 저장.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")

        # 모든 token에 대해, 각 토큰의 원래 문장에서의 위치값(시작, 끝) 정보 저장.
        offset_mapping = tokenized_examples.pop("offset_mapping")

        # Let's label those examples!
        tokenized_examples["start_positions"] = []
        tokenized_examples["end_positions"] = []

        for i, offsets in enumerate(offset_mapping):
            # We will label impossible answers with the index of the CLS token.
            input_ids = tokenized_examples["input_ids"][i]
            cls_index = input_ids.index(tokenizer.cls_token_id)

            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            # sequence_ids -> cls, 질문, cls, 문단, end 구분 기능 -> [None, 0, 0, ..., 0, None, 1, 1, ...., 1, None] 
            sequence_ids = tokenized_examples.sequence_ids(i)

            # One example can give several spans, this is the index of the example containing this span of text.
            # 지금 보고있는 i 번째 tokenized 결과가 어느 context로 만들어졌는지 그 번호 찾음. 
            sample_index = sample_mapping[i]
            
            answers = examples[answer_column_name][sample_index]
            # print(answers)
            # If no answers are given, set the cls_index as answer.
            if len(answers["answer_start"]) == 0:
                tokenized_examples["start_positions"].append(cls_index)
                tokenized_examples["end_positions"].append(cls_index)
            else:
                # Start/end character index of the answer in the text.
                start_char = answers["answer_start"][0]
                end_char = start_char + len(answers["text"][0])

                # Start token index of the current span in the text.
                token_start_index = 0
                while sequence_ids[token_start_index] != (1 if pad_on_right else 0):
                    token_start_index += 1

                # End token index of the current span in the text.
                token_end_index = len(input_ids) - 1
                while sequence_ids[token_end_index] != (1 if pad_on_right else 0):
                    token_end_index -= 1

                # Detect if the answer is out of the span (in which case this feature is labeled with the CLS index).
                if not (
                    offsets[token_start_index][0] <= start_char
                    and offsets[token_end_index][1] >= end_char
                ):
                    tokenized_examples["start_positions"].append(cls_index)
                    tokenized_examples["end_positions"].append(cls_index)
                else:
                    # Otherwise move the token_start_index and token_end_index to the two ends of the answer.
                    # Note: we could go after the last offset if the answer is the last word (edge case).
                    while (
                        token_start_index < len(offsets)
                        and offsets[token_start_index][0] <= start_char
                    ):
                        token_start_index += 1
                    tokenized_examples["start_positions"].append(token_start_index - 1)
                    while offsets[token_end_index][1] >= end_char:
                        token_end_index -= 1
                    tokenized_examples["end_positions"].append(token_end_index + 1)

        return tokenized_examples

    if "train" not in datasets:
        raise ValueError("--do_train requires a train dataset")

    column_names = datasets["train"].column_names
    train_dataset = datasets["train"]

    train_dataset = train_dataset.map(
        prepare_train_features,
        batched=True,
        num_proc=data_args.preprocessing_num_workers,
        remove_columns=column_names,
        load_from_cache_file=not data_args.overwrite_cache,
    )

    ## validation 데이터 가공 과정
    def prepare_validation_features(examples):
        tokenized_examples = tokenizer(
            examples[question_column_name if pad_on_right else context_column_name],
            examples[context_column_name if pad_on_right else question_column_name],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=max_seq_length,
            stride=data_args.doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            padding="max_length" if data_args.pad_to_max_length else False,
        )

        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")

        tokenized_examples["example_id"] = []

        for i in range(len(tokenized_examples["input_ids"])):
            sequence_ids = tokenized_examples.sequence_ids(i)
            context_index = 1 if pad_on_right else 0

            sample_index = sample_mapping[i]
            tokenized_examples["example_id"].append(examples["id"][sample_index])

            # Set to None the offset_mapping that are not part of the context so it's easy to determine if a token
            # position is part of the context or not.
            # offset_mapping : 각 토큰의 (시작위치, 끝 위치) 정보를 담고 있는데, 
            # query 토큰들의 (시작위치, 끝 위치) 정보를 None으로 바꾸는 과정
            # 왜? validation 할 때, output 으로 start logit과 end logit을 받게 된다. 
            # 이때 해당 인덱스를 query 가 아닌 passage에서 찾기 위함.
            tokenized_examples["offset_mapping"][i] = [
                (o if sequence_ids[k] == context_index else None)
                for k, o in enumerate(tokenized_examples["offset_mapping"][i])
            ]
        return tokenized_examples

    eval_dataset = datasets["validation"]
    column_names = datasets["validation"].column_names

    eval_dataset = eval_dataset.map(
        prepare_validation_features,
        batched=True,
        num_proc=data_args.preprocessing_num_workers,
        remove_columns=column_names,
        load_from_cache_file=not data_args.overwrite_cache,
    )

    # Data collator
    # We have already padded to max length if the corresponding flag is True, otherwise we need to pad in the data collator.
    # pad_to_multiple_of : mixed precision을 사용할 때, 텐서 사이즈가 8의 배수일때 더 효과적이다.'
    # 따라서,(Funnel Transformer? 뭔지 모르겠지만 이건 32로 세팅) 8로 세팅해서 max_length을 조절 하게 된다. 
    # 근데 이미 tokeneizer가 max_length를 384로 처리하고 있어서 작동 안할 듯.
    data_collator = (
        DataCollatorWithPadding(
            tokenizer, pad_to_multiple_of=8 if training_args.fp16 else None
        )
    )

    # Post-processing : 
    def post_processing_function(examples, features, predictions, training_args):
        # Post-processing: we match the start logits and end logits to answers in the original context.
        predictions = postprocess_qa_predictions(
            examples=examples,
            features=features,
            predictions=predictions,
            max_answer_length=data_args.max_answer_length,
            output_dir=training_args.output_dir,
        )
       # Format the result to the format the metric expects.
        formatted_predictions = [
            {"id": k, "prediction_text": v} for k, v in predictions.items()
        ]

        if training_args.do_predict:
            return formatted_predictions        
        else:
            references = [
                {"id": ex["id"], "answers": ex[answer_column_name]}
                for ex in datasets["validation"]
            ]
            return EvalPrediction(predictions=formatted_predictions, label_ids=references)

    metric = load_metric("squad")

    metric_key_prefix = 'eval'   
    def compute_metrics(p: EvalPrediction):
        before_prefix_metrics = metric.compute(predictions=p.predictions, references=p.label_ids)
        metrics ={f'{metric_key_prefix}_{k}':v for k,v in before_prefix_metrics.items()}        
        return metrics
    
    # early stop 조건
    early_stopping = EarlyStoppingCallback(early_stopping_patience = 50, early_stopping_threshold = 0.2)
    
    # QuestionAnsweringTrainer
    trainer = QuestionAnsweringTrainer(
        model=model,
        args=training_args,
        train_dataset=train_dataset,
        eval_dataset=eval_dataset,
        eval_examples=datasets["validation"],
        tokenizer=tokenizer,
        data_collator=data_collator,
        post_process_function=post_processing_function,
        compute_metrics=compute_metrics,
        callbacks=[early_stopping],
    )
   
    # Training 
    if last_checkpoint is not None:
        checkpoint = last_checkpoint
    elif os.path.isdir(model_args.model_name_or_path):
        checkpoint = model_args.model_name_or_path
    else:
        checkpoint = None

    train_result = trainer.train(resume_from_checkpoint=checkpoint)

    metrics = train_result.metrics
    metrics["train_samples"] = len(train_dataset)

    trainer.log_metrics("train", metrics)
    
    output_train_file = os.path.join(training_args.output_dir, "train_results.txt")

    with open(output_train_file, "w") as writer:
        logger.info("***** Train results *****")
        for key, value in sorted(train_result.metrics.items()):
            logger.info(f"  {key} = {value}")
            writer.write(f"{key} = {value}\n")
Example #8
0
def main(_):
    checkpoint = os.path.join(FLAGS.save_dir, FLAGS.cp)
    if not os.path.isdir(FLAGS.save_dir):
        os.mkdir(FLAGS.save_dir)
    # Build model
    if FLAGS.REL:
        if os.path.isdir(checkpoint):
            logging.info('Loading from {}'.format(checkpoint))
            config = AutoConfig.from_pretrained(checkpoint)
        else:
            config = AutoConfig.from_pretrained(model_pretrain)
        config.position_embedding_type = "relative_key_query"
        model = AutoModelForQuestionAnswering.from_config(config)
    else:
        if os.path.isdir(checkpoint):
            logging.info('Loading from {}'.format(checkpoint))
            model = AutoModelForQuestionAnswering.from_pretrained(checkpoint)
        else:
            model = AutoModelForQuestionAnswering.from_pretrained(
                model_pretrain)
    # Tokenizer
    tokenizer = AutoTokenizer.from_pretrained(
        model_pretrain,
        use_fast=True,
    )
    if FLAGS.TOK:
        tokenizer.add_tokens(hyper_tokens, special_tokens=True)
        model.resize_token_embeddings(len(tokenizer))

    # dataset
    # Validation preprocessing
    def prepare_validation_features(examples):
        # Tokenize our examples with truncation and maybe padding, but keep the overflows using a stride. This results
        # in one example possible giving several features when a context is long, each of those features having a
        # context that overlaps a bit the context of the previous feature.

        tokenized_examples = tokenizer(
            examples["question" if pad_on_right else "context"],
            examples["context" if pad_on_right else "question"],
            truncation="only_second" if pad_on_right else "only_first",
            max_length=max_length,
            stride=doc_stride,
            return_overflowing_tokens=True,
            return_offsets_mapping=True,
            padding="max_length",
        )
        # Since one example might give us several features if it has a long context, we need a map from a feature to
        # its corresponding example. This key gives us just that.
        sample_mapping = tokenized_examples.pop("overflow_to_sample_mapping")

        offset_mapping = tokenized_examples["offset_mapping"]

        # Let's label those examples!
        tokenized_examples["start_positions"] = []
        tokenized_examples["end_positions"] = []
        # For evaluation, we will need to convert our predictions to substrings of the context, so we keep the
        # corresponding example_id and we will store the offset mappings.
        tokenized_examples["example_id"] = []

        for i, offsets in enumerate(offset_mapping):
            # We will label impossible answers with the index of the CLS token.
            input_ids = tokenized_examples["input_ids"][i]
            cls_index = input_ids.index(tokenizer.cls_token_id)

            # Grab the sequence corresponding to that example (to know what is the context and what is the question).
            sequence_ids = tokenized_examples.sequence_ids(i)
            context_index = 1 if pad_on_right else 0

            # One example can give several spans, this is the index of the example containing this span of text.
            sample_index = sample_mapping[i]
            tokenized_examples["example_id"].append(
                examples["id"][sample_index])

            # Set to None the offset_mapping that are not part of the context so it's easy to determine if a token
            # position is part of the context or not.
            tokenized_examples["offset_mapping"][i] = [
                (o if sequence_ids[k] == context_index else None)
                for k, o in enumerate(tokenized_examples["offset_mapping"][i])
            ]

            ## TODO for gz file
            start_char, end_char = -1, -1
            # Start/end character index of the answer in the text.
            for candidate in examples["annotations"][sample_index]:
                cur = candidate["long_answer"]["start_char"]
                if cur != -1:
                    start_char = cur
                    end_char = candidate["long_answer"]["end_char"]
            # If no answers are given, set the cls_index as answer.
            if start_char == -1:
                tokenized_examples["start_positions"].append(cls_index)
                tokenized_examples["end_positions"].append(cls_index)
            else:

                # Start token index of the current span in the text.
                token_start_index = 0
                while sequence_ids[token_start_index] != (1 if pad_on_right
                                                          else 0):
                    token_start_index += 1

                # End token index of the current span in the text.
                token_end_index = len(input_ids) - 1
                while sequence_ids[token_end_index] != (1 if pad_on_right else
                                                        0):
                    token_end_index -= 1

                # Detect if the answer is out of the span (in which case this feature is labeled with the CLS index).
                if not (offsets[token_start_index][0] <= start_char
                        and offsets[token_end_index][1] >= end_char):
                    tokenized_examples["start_positions"].append(cls_index)
                    tokenized_examples["end_positions"].append(cls_index)
                else:
                    # Otherwise move the token_start_index and token_end_index to the two ends of the answer.
                    # Note: we could go after the last offset if the answer is the last word (edge case).
                    while token_start_index < len(offsets) and offsets[
                            token_start_index][0] <= start_char:
                        token_start_index += 1
                    tokenized_examples["start_positions"].append(
                        token_start_index - 1)
                    while offsets[token_end_index][1] >= end_char:
                        token_end_index -= 1
                    tokenized_examples["end_positions"].append(
                        token_end_index + 1)

        return tokenized_examples

    pad_on_right = tokenizer.padding_side == "right"

    train_dataset = load_from_disk(
        os.path.join(FLAGS.data_dir, FLAGS.train_name)).shuffle(seed=1)

    eval_dataset = load_from_disk(os.path.join(FLAGS.data_dir, "valid_50"))
    eval_examples = load_from_disk(
        os.path.join(FLAGS.data_dir, "example_valid_50"))

    args = TrainingArguments(
        FLAGS.save_dir,
        learning_rate=3e-5,
        per_device_train_batch_size=FLAGS.batch_size,
        per_device_eval_batch_size=FLAGS.batch_size * 16,
        num_train_epochs=FLAGS.epochs,
        save_steps=FLAGS.steps,
        eval_steps=FLAGS.steps,
        logging_steps=FLAGS.steps,
        evaluation_strategy='steps',
        gradient_accumulation_steps=8,
    )

    data_collator = default_data_collator

    # Initialize Trainer
    trainer = QuestionAnsweringTrainer(
        model=model,
        args=args,
        train_dataset=train_dataset,
        eval_dataset=eval_dataset,
        eval_examples=eval_examples,
        tokenizer=tokenizer,
        data_collator=data_collator,
    )
    if os.path.isdir(checkpoint):
        train_result = trainer.train(resume_from_checkpoint=checkpoint)
    else:
        trainer.train()

    trainer.save_model(os.path.join(FLAGS.save_dir, 'last'))