[examples] Add trainer support for question-answering (#4829)

* add SquadDataset

* add DataCollatorForQuestionAnswering

* update __init__

* add run_squad with  trainer

* add DataCollatorForQuestionAnswering in __init__

* pass data_collator to trainer

* doc tweak

* Update run_squad_trainer.py

* Update __init__.py

* Update __init__.py
Co-authored-by: Julien Chaumond <chaumond@gmail.com>
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

examples/question-answering/README.md

@@ -77,7 +77,7 @@ exact_match = 86.91
 ```
 
 This fine-tuned model is available as a checkpoint under the reference
-`bert-large-uncased-whole-word-masking-finetuned-squad`.
+[`bert-large-uncased-whole-word-masking-finetuned-squad`](https://huggingface.co/bert-large-uncased-whole-word-masking-finetuned-squad).
 
 #### Fine-tuning XLNet on SQuAD
 
@@ -176,4 +176,5 @@ python run_tf_squad.py \
     --doc_stride 128    
 ```
 
-For the moment the evaluation is not available in the Tensorflow Trainer only the training.
+
+For the moment evaluation is not available in the Tensorflow Trainer only the training.

examples/question-answering/run_squad_trainer.py

+# coding=utf-8
+# Copyright 2018 The Google AI Language Team Authors and The HuggingFace Inc. team.
+# Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+""" Fine-tuning the library models for question-answering."""
+
+
+import logging
+import os
+import sys
+from dataclasses import dataclass, field
+from typing import Optional
+
+from transformers import AutoConfig, AutoModelForQuestionAnswering, AutoTokenizer, HfArgumentParser, SquadDataset
+from transformers import SquadDataTrainingArguments as DataTrainingArguments
+from transformers import Trainer, TrainingArguments
+
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class ModelArguments:
+    """
+    Arguments pertaining to which model/config/tokenizer we are going to fine-tune from.
+    """
+
+    model_name_or_path: str = field(
+        metadata={"help": "Path to pretrained model or model identifier from huggingface.co/models"}
+    )
+    config_name: Optional[str] = field(
+        default=None, metadata={"help": "Pretrained config name or path if not the same as model_name"}
+    )
+    tokenizer_name: Optional[str] = field(
+        default=None, metadata={"help": "Pretrained tokenizer name or path if not the same as model_name"}
+    )
+    use_fast: bool = field(default=False, metadata={"help": "Set this flag to use fast tokenization."})
+    # If you want to tweak more attributes on your tokenizer, you should do it in a distinct script,
+    # or just modify its tokenizer_config.json.
+    cache_dir: Optional[str] = field(
+        default=None, metadata={"help": "Where do you want to store the pretrained models downloaded from s3"}
+    )
+
+
+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",
+        level=logging.INFO if training_args.local_rank in [-1, 0] else logging.WARN,
+    )
+    logger.warning(
+        "Process rank: %s, device: %s, n_gpu: %s, distributed training: %s, 16-bits training: %s",
+        training_args.local_rank,
+        training_args.device,
+        training_args.n_gpu,
+        bool(training_args.local_rank != -1),
+        training_args.fp16,
+    )
+    logger.info("Training/evaluation parameters %s", training_args)
+
+    # Prepare Question-Answering task
+    # 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,
+    )
+    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,
+    )
+
+    # Get datasets
+    is_language_sensitive = hasattr(model.config, "lang2id")
+    train_dataset = (
+        SquadDataset(
+            data_args, tokenizer=tokenizer, is_language_sensitive=is_language_sensitive, cache_dir=model_args.cache_dir
+        )
+        if training_args.do_train
+        else None
+    )
+    eval_dataset = (
+        SquadDataset(
+            data_args,
+            tokenizer=tokenizer,
+            mode="dev",
+            is_language_sensitive=is_language_sensitive,
+            cache_dir=model_args.cache_dir,
+        )
+        if training_args.do_eval
+        else None
+    )
+
+    # Initialize our Trainer
+    trainer = Trainer(model=model, args=training_args, train_dataset=train_dataset, eval_dataset=eval_dataset,)
+
+    # 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()
+        # For convenience, we also re-save the tokenizer to the same directory,
+        # so that you can share your model easily on huggingface.co/models =)
+        if trainer.is_world_master():
+            tokenizer.save_pretrained(training_args.output_dir)
+
+
+def _mp_fn(index):
+    # For xla_spawn (TPUs)
+    main()
+
+
+if __name__ == "__main__":
+    main()

src/transformers/__init__.py

@@ -416,14 +416,21 @@ if is_torch_available():
     )
 
     # Trainer
-    from .trainer import Trainer, torch_distributed_zero_first
+    from .trainer import Trainer, set_seed, torch_distributed_zero_first, EvalPrediction
     from .data.data_collator import (
         default_data_collator,
         DataCollator,
         DataCollatorForLanguageModeling,
         DataCollatorForPermutationLanguageModeling,
     )
-    from .data.datasets import GlueDataset, TextDataset, LineByLineTextDataset, GlueDataTrainingArguments
+    from .data.datasets import (
+        GlueDataset,
+        TextDataset,
+        LineByLineTextDataset,
+        GlueDataTrainingArguments,
+        SquadDataset,
+        SquadDataTrainingArguments,
+    )
 
     # Benchmarks
     from .benchmark.benchmark import PyTorchBenchmark

src/transformers/data/datasets/__init__.py

@@ -4,3 +4,4 @@
 
 from .glue import GlueDataset, GlueDataTrainingArguments
 from .language_modeling import LineByLineTextDataset, TextDataset
+from .squad import SquadDataset, SquadDataTrainingArguments

src/transformers/data/datasets/squad.py

+import logging
+import os
+import time
+from dataclasses import dataclass, field
+from enum import Enum
+from typing import Dict, List, Optional, Union
+
+import torch
+from filelock import FileLock
+from torch.utils.data.dataset import Dataset
+
+from ...modeling_auto import MODEL_FOR_QUESTION_ANSWERING_MAPPING
+from ...tokenization_utils import PreTrainedTokenizer
+from ..processors.squad import SquadFeatures, SquadV1Processor, SquadV2Processor, squad_convert_examples_to_features
+
+
+logger = logging.getLogger(__name__)
+
+MODEL_CONFIG_CLASSES = list(MODEL_FOR_QUESTION_ANSWERING_MAPPING.keys())
+MODEL_TYPES = tuple(conf.model_type for conf in MODEL_CONFIG_CLASSES)
+
+
+@dataclass
+class SquadDataTrainingArguments:
+    """
+    Arguments pertaining to what data we are going to input our model for training and eval.
+    """
+
+    model_type: str = field(
+        default=None, metadata={"help": "Model type selected in the list: " + ", ".join(MODEL_TYPES)}
+    )
+    data_dir: str = field(
+        default=None, metadata={"help": "The input data dir. Should contain the .json files for the SQuAD task."}
+    )
+    max_seq_length: int = field(
+        default=128,
+        metadata={
+            "help": "The maximum total input sequence length after tokenization. Sequences longer "
+            "than this will be truncated, sequences shorter will be padded."
+        },
+    )
+    doc_stride: int = field(
+        default=128,
+        metadata={"help": "When splitting up a long document into chunks, how much stride to take between chunks."},
+    )
+    max_query_length: int = field(
+        default=64,
+        metadata={
+            "help": "The maximum number of tokens for the question. Questions longer than this will "
+            "be truncated to this length."
+        },
+    )
+    max_answer_length: int = field(
+        default=30,
+        metadata={
+            "help": "The maximum length of an answer that can be generated. This is needed because the start "
+            "and end predictions are not conditioned on one another."
+        },
+    )
+    overwrite_cache: bool = field(
+        default=False, metadata={"help": "Overwrite the cached training and evaluation sets"}
+    )
+    version_2_with_negative: bool = field(
+        default=False, metadata={"help": "If true, the SQuAD examples contain some that do not have an answer."}
+    )
+    null_score_diff_threshold: float = field(
+        default=0.0, metadata={"help": "If null_score - best_non_null is greater than the threshold predict null."}
+    )
+    n_best_size: int = field(
+        default=20, metadata={"help": "If null_score - best_non_null is greater than the threshold predict null."}
+    )
+    lang_id: int = field(
+        default=0,
+        metadata={
+            "help": "language id of input for language-specific xlm models (see tokenization_xlm.PRETRAINED_INIT_CONFIGURATION)"
+        },
+    )
+    threads: int = field(default=1, metadata={"help": "multiple threads for converting example to features"})
+
+
+class Split(Enum):
+    train = "train"
+    dev = "dev"
+
+
+class SquadDataset(Dataset):
+    """
+    This will be superseded by a framework-agnostic approach
+    soon.
+    """
+
+    args: SquadDataTrainingArguments
+    features: List[SquadFeatures]
+    mode: Split
+    is_language_sensitive: bool
+
+    def __init__(
+        self,
+        args: SquadDataTrainingArguments,
+        tokenizer: PreTrainedTokenizer,
+        limit_length: Optional[int] = None,
+        mode: Union[str, Split] = Split.train,
+        is_language_sensitive: Optional[bool] = False,
+        cache_dir: Optional[str] = None,
+    ):
+        self.args = args
+        self.is_language_sensitive = is_language_sensitive
+        self.processor = SquadV2Processor() if args.version_2_with_negative else SquadV1Processor()
+        if isinstance(mode, str):
+            try:
+                mode = Split[mode]
+            except KeyError:
+                raise KeyError("mode is not a valid split name")
+        self.mode = mode
+        # Load data features from cache or dataset file
+        cached_features_file = os.path.join(
+            cache_dir if cache_dir is not None else args.data_dir,
+            "cached_{}_{}_{}".format(mode.value, tokenizer.__class__.__name__, str(args.max_seq_length),),
+        )
+
+        # Make sure only the first process in distributed training processes the dataset,
+        # and the others will use the cache.
+        lock_path = cached_features_file + ".lock"
+        with FileLock(lock_path):
+            if os.path.exists(cached_features_file) and not args.overwrite_cache:
+                start = time.time()
+                self.features = torch.load(cached_features_file)
+                logger.info(
+                    f"Loading features from cached file {cached_features_file} [took %.3f s]", time.time() - start
+                )
+            else:
+                if mode == Split.dev:
+                    examples = self.processor.get_dev_examples(args.data_dir)
+                else:
+                    examples = self.processor.get_train_examples(args.data_dir)
+
+                self.features = squad_convert_examples_to_features(
+                    examples=examples,
+                    tokenizer=tokenizer,
+                    max_seq_length=args.max_seq_length,
+                    doc_stride=args.doc_stride,
+                    max_query_length=args.max_query_length,
+                    is_training=mode == Split.train,
+                    threads=args.threads,
+                )
+
+                start = time.time()
+                torch.save(self.features, cached_features_file)
+                # ^ This seems to take a lot of time so I want to investigate why and how we can improve.
+                logger.info(
+                    "Saving features into cached file %s [took %.3f s]", cached_features_file, time.time() - start
+                )
+
+    def __len__(self):
+        return len(self.features)
+
+    def __getitem__(self, i) -> Dict[str, torch.Tensor]:
+        # Convert to Tensors and build dataset
+        feature = self.features[i]
+
+        input_ids = torch.tensor(feature.input_ids, dtype=torch.long)
+        attention_mask = torch.tensor(feature.attention_mask, dtype=torch.long)
+        token_type_ids = torch.tensor(feature.token_type_ids, dtype=torch.long)
+        cls_index = torch.tensor(feature.cls_index, dtype=torch.long)
+        p_mask = torch.tensor(feature.p_mask, dtype=torch.float)
+        is_impossible = torch.tensor(feature.is_impossible, dtype=torch.float)
+
+        inputs = {
+            "input_ids": input_ids,
+            "attention_mask": attention_mask,
+            "token_type_ids": token_type_ids,
+        }
+
+        if self.args.model_type in ["xlm", "roberta", "distilbert", "camembert"]:
+            del inputs["token_type_ids"]
+
+        if self.args.model_type in ["xlnet", "xlm"]:
+            inputs.update({"cls_index": cls_index, "p_mask": p_mask})
+            if self.args.version_2_with_negative:
+                inputs.update({"is_impossible": is_impossible})
+            if self.is_language_sensitive:
+                inputs.update({"langs": (torch.ones(input_ids.shape, dtype=torch.int64) * self.args.lang_id)})
+
+        if self.mode == Split.train:
+            start_positions = torch.tensor(feature.start_position, dtype=torch.long)
+            end_positions = torch.tensor(feature.end_position, dtype=torch.long)
+            inputs.update({"start_positions": start_positions, "end_positions": end_positions})
+
+        return inputs