Finetune Transformers Models with PyTorch Lightning

  • Author: Lightning.ai

  • License: CC BY-SA

  • Generated: 2024-07-26T13:13:57.667341

This notebook will use HuggingFace’s datasets library to get data, which will be wrapped in a LightningDataModule. Then, we write a class to perform text classification on any dataset from the GLUE Benchmark. (We just show CoLA and MRPC due to constraint on compute/disk)


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Setup

This notebook requires some packages besides pytorch-lightning.

[1]:
! pip install --quiet "scipy" "datasets" "transformers" "torch>=1.8.1, <2.5" "torchmetrics>=1.0, <1.5" "torchmetrics >=1.0, <1.2" "torch ==2.1.*" "numpy <2.0" "scikit-learn" "torchvision ==0.16.*" "matplotlib" "pytorch-lightning >=2.0,<2.4" "torchtext"
WARNING: Running pip as the 'root' user can result in broken permissions and conflicting behaviour with the system package manager, possibly rendering your system unusable.It is recommended to use a virtual environment instead: https://pip.pypa.io/warnings/venv. Use the --root-user-action option if you know what you are doing and want to suppress this warning.

[2]:
from collections import defaultdict
from datetime import datetime
from typing import Optional

import datasets
import pytorch_lightning as pl
import torch
from torch.utils.data import DataLoader
from transformers import (
    AdamW,
    AutoConfig,
    AutoModelForSequenceClassification,
    AutoTokenizer,
    get_linear_schedule_with_warmup,
)

Training BERT with Lightning

Lightning DataModule for GLUE

[3]:
class GLUEDataModule(pl.LightningDataModule):
    task_text_field_map = {
        "cola": ["sentence"],
        "sst2": ["sentence"],
        "mrpc": ["sentence1", "sentence2"],
        "qqp": ["question1", "question2"],
        "stsb": ["sentence1", "sentence2"],
        "mnli": ["premise", "hypothesis"],
        "qnli": ["question", "sentence"],
        "rte": ["sentence1", "sentence2"],
        "wnli": ["sentence1", "sentence2"],
        "ax": ["premise", "hypothesis"],
    }

    glue_task_num_labels = {
        "cola": 2,
        "sst2": 2,
        "mrpc": 2,
        "qqp": 2,
        "stsb": 1,
        "mnli": 3,
        "qnli": 2,
        "rte": 2,
        "wnli": 2,
        "ax": 3,
    }

    loader_columns = [
        "datasets_idx",
        "input_ids",
        "token_type_ids",
        "attention_mask",
        "start_positions",
        "end_positions",
        "labels",
    ]

    def __init__(
        self,
        model_name_or_path: str,
        task_name: str = "mrpc",
        max_seq_length: int = 128,
        train_batch_size: int = 32,
        eval_batch_size: int = 32,
        **kwargs,
    ):
        super().__init__()
        self.model_name_or_path = model_name_or_path
        self.task_name = task_name
        self.max_seq_length = max_seq_length
        self.train_batch_size = train_batch_size
        self.eval_batch_size = eval_batch_size

        self.text_fields = self.task_text_field_map[task_name]
        self.num_labels = self.glue_task_num_labels[task_name]
        self.tokenizer = AutoTokenizer.from_pretrained(self.model_name_or_path, use_fast=True)

    def setup(self, stage=None):
        self.dataset = datasets.load_dataset("glue", self.task_name)

        for split in self.dataset.keys():
            self.dataset[split] = self.dataset[split].map(
                self.convert_to_features,
                batched=True,
                remove_columns=["label"],
            )
            self.columns = [c for c in self.dataset[split].column_names if c in self.loader_columns]
            self.dataset[split].set_format(type="torch", columns=self.columns)

        self.eval_splits = [x for x in self.dataset.keys() if "validation" in x]

    def prepare_data(self):
        datasets.load_dataset("glue", self.task_name)
        AutoTokenizer.from_pretrained(self.model_name_or_path, use_fast=True)

    def train_dataloader(self):
        return DataLoader(self.dataset["train"], batch_size=self.train_batch_size, shuffle=True)

    def val_dataloader(self):
        if len(self.eval_splits) == 1:
            return DataLoader(self.dataset["validation"], batch_size=self.eval_batch_size)
        elif len(self.eval_splits) > 1:
            return [DataLoader(self.dataset[x], batch_size=self.eval_batch_size) for x in self.eval_splits]

    def test_dataloader(self):
        if len(self.eval_splits) == 1:
            return DataLoader(self.dataset["test"], batch_size=self.eval_batch_size)
        elif len(self.eval_splits) > 1:
            return [DataLoader(self.dataset[x], batch_size=self.eval_batch_size) for x in self.eval_splits]

    def convert_to_features(self, example_batch, indices=None):
        # Either encode single sentence or sentence pairs
        if len(self.text_fields) > 1:
            texts_or_text_pairs = list(zip(example_batch[self.text_fields[0]], example_batch[self.text_fields[1]]))
        else:
            texts_or_text_pairs = example_batch[self.text_fields[0]]

        # Tokenize the text/text pairs
        features = self.tokenizer.batch_encode_plus(
            texts_or_text_pairs, max_length=self.max_seq_length, pad_to_max_length=True, truncation=True
        )

        # Rename label to labels to make it easier to pass to model forward
        features["labels"] = example_batch["label"]

        return features

You could use this datamodule with standalone PyTorch if you wanted…

[4]:
dm = GLUEDataModule("distilbert-base-uncased")
dm.prepare_data()
dm.setup("fit")
next(iter(dm.train_dataloader()))
/usr/local/lib/python3.10/dist-packages/transformers/tokenization_utils_base.py:2888: FutureWarning: The `pad_to_max_length` argument is deprecated and will be removed in a future version, use `padding=True` or `padding='longest'` to pad to the longest sequence in the batch, or use `padding='max_length'` to pad to a max length. In this case, you can give a specific length with `max_length` (e.g. `max_length=45`) or leave max_length to None to pad to the maximal input size of the model (e.g. 512 for Bert).
  warnings.warn(
[4]:
{'input_ids': tensor([[  101,  2035,  2216,  ...,     0,     0,     0],
         [  101,  1000,  1996,  ...,     0,     0,     0],
         [  101,  2021, 24040,  ...,     0,     0,     0],
         ...,
         [  101,  3463,  2013,  ...,     0,     0,     0],
         [  101,  2027,  2056,  ...,     0,     0,     0],
         [  101,  4584,  2012,  ...,     0,     0,     0]]),
 'attention_mask': tensor([[1, 1, 1,  ..., 0, 0, 0],
         [1, 1, 1,  ..., 0, 0, 0],
         [1, 1, 1,  ..., 0, 0, 0],
         ...,
         [1, 1, 1,  ..., 0, 0, 0],
         [1, 1, 1,  ..., 0, 0, 0],
         [1, 1, 1,  ..., 0, 0, 0]]),
 'labels': tensor([1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1,
         0, 0, 1, 1, 0, 0, 1, 1])}

Transformer LightningModule

[5]:
class GLUETransformer(pl.LightningModule):
    def __init__(
        self,
        model_name_or_path: str,
        num_labels: int,
        task_name: str,
        learning_rate: float = 2e-5,
        adam_epsilon: float = 1e-8,
        warmup_steps: int = 0,
        weight_decay: float = 0.0,
        train_batch_size: int = 32,
        eval_batch_size: int = 32,
        eval_splits: Optional[list] = None,
        **kwargs,
    ):
        super().__init__()

        self.save_hyperparameters()

        self.config = AutoConfig.from_pretrained(model_name_or_path, num_labels=num_labels)
        self.model = AutoModelForSequenceClassification.from_pretrained(model_name_or_path, config=self.config)
        self.metric = datasets.load_metric(
            "glue",
            self.hparams.task_name,
            experiment_id=datetime.now().strftime("%d-%m-%Y_%H-%M-%S"),
            trust_remote_code=True,
        )
        self.outputs = defaultdict(list)

    def forward(self, **inputs):
        return self.model(**inputs)

    def training_step(self, batch, batch_idx):
        outputs = self(**batch)
        loss = outputs[0]
        return loss

    def validation_step(self, batch, batch_idx, dataloader_idx=0):
        outputs = self(**batch)
        val_loss, logits = outputs[:2]

        if self.hparams.num_labels > 1:
            preds = torch.argmax(logits, axis=1)
        elif self.hparams.num_labels == 1:
            preds = logits.squeeze()

        labels = batch["labels"]

        self.outputs[dataloader_idx].append({"loss": val_loss, "preds": preds, "labels": labels})

    def on_validation_epoch_end(self):
        if self.hparams.task_name == "mnli":
            for i, outputs in self.outputs.items():
                # matched or mismatched
                split = self.hparams.eval_splits[i].split("_")[-1]
                preds = torch.cat([x["preds"] for x in outputs]).detach().cpu().numpy()
                labels = torch.cat([x["labels"] for x in outputs]).detach().cpu().numpy()
                loss = torch.stack([x["loss"] for x in outputs]).mean()
                self.log(f"val_loss_{split}", loss, prog_bar=True)
                split_metrics = {
                    f"{k}_{split}": v for k, v in self.metric.compute(predictions=preds, references=labels).items()
                }
                self.log_dict(split_metrics, prog_bar=True)
            return loss

        flat_outputs = []
        for lst in self.outputs.values():
            flat_outputs.extend(lst)

        preds = torch.cat([x["preds"] for x in flat_outputs]).detach().cpu().numpy()
        labels = torch.cat([x["labels"] for x in flat_outputs]).detach().cpu().numpy()
        loss = torch.stack([x["loss"] for x in flat_outputs]).mean()
        self.log("val_loss", loss, prog_bar=True)
        self.log_dict(self.metric.compute(predictions=preds, references=labels), prog_bar=True)
        self.outputs.clear()

    def configure_optimizers(self):
        """Prepare optimizer and schedule (linear warmup and decay)."""
        model = self.model
        no_decay = ["bias", "LayerNorm.weight"]
        optimizer_grouped_parameters = [
            {
                "params": [p for n, p in model.named_parameters() if not any(nd in n for nd in no_decay)],
                "weight_decay": self.hparams.weight_decay,
            },
            {
                "params": [p for n, p in model.named_parameters() if any(nd in n for nd in no_decay)],
                "weight_decay": 0.0,
            },
        ]
        optimizer = AdamW(optimizer_grouped_parameters, lr=self.hparams.learning_rate, eps=self.hparams.adam_epsilon)

        scheduler = get_linear_schedule_with_warmup(
            optimizer,
            num_warmup_steps=self.hparams.warmup_steps,
            num_training_steps=self.trainer.estimated_stepping_batches,
        )
        scheduler = {"scheduler": scheduler, "interval": "step", "frequency": 1}
        return [optimizer], [scheduler]

Training

CoLA

See an interactive view of the CoLA dataset in NLP Viewer

[6]:
pl.seed_everything(42)

dm = GLUEDataModule(model_name_or_path="albert-base-v2", task_name="cola")
dm.setup("fit")
model = GLUETransformer(
    model_name_or_path="albert-base-v2",
    num_labels=dm.num_labels,
    eval_splits=dm.eval_splits,
    task_name=dm.task_name,
)

trainer = pl.Trainer(
    max_epochs=1,
    accelerator="auto",
    devices=1,
)
trainer.fit(model, datamodule=dm)
Seed set to 42
Some weights of AlbertForSequenceClassification were not initialized from the model checkpoint at albert-base-v2 and are newly initialized: ['classifier.bias', 'classifier.weight']
You should probably TRAIN this model on a down-stream task to be able to use it for predictions and inference.
/tmp/ipykernel_816/3306335502.py:22: FutureWarning: load_metric is deprecated and will be removed in the next major version of datasets. Use 'evaluate.load' instead, from the new library 🤗 Evaluate: https://huggingface.co/docs/evaluate
  self.metric = datasets.load_metric(
GPU available: True (cuda), used: True
TPU available: False, using: 0 TPU cores
HPU available: False, using: 0 HPUs
/usr/local/lib/python3.10/dist-packages/pytorch_lightning/trainer/connectors/logger_connector/logger_connector.py:75: Starting from v1.9.0, `tensorboardX` has been removed as a dependency of the `pytorch_lightning` package, due to potential conflicts with other packages in the ML ecosystem. For this reason, `logger=True` will use `CSVLogger` as the default logger, unless the `tensorboard` or `tensorboardX` packages are found. Please `pip install lightning[extra]` or one of them to enable TensorBoard support by default
You are using a CUDA device ('NVIDIA GeForce RTX 3090') that has Tensor Cores. To properly utilize them, you should set `torch.set_float32_matmul_precision('medium' | 'high')` which will trade-off precision for performance. For more details, read https://pytorch.org/docs/stable/generated/torch.set_float32_matmul_precision.html#torch.set_float32_matmul_precision
Missing logger folder: /__w/13/s/lightning_logs
/usr/local/lib/python3.10/dist-packages/transformers/tokenization_utils_base.py:2888: FutureWarning: The `pad_to_max_length` argument is deprecated and will be removed in a future version, use `padding=True` or `padding='longest'` to pad to the longest sequence in the batch, or use `padding='max_length'` to pad to a max length. In this case, you can give a specific length with `max_length` (e.g. `max_length=45`) or leave max_length to None to pad to the maximal input size of the model (e.g. 512 for Bert).
  warnings.warn(
LOCAL_RANK: 0 - CUDA_VISIBLE_DEVICES: [0,1]
/usr/local/lib/python3.10/dist-packages/transformers/optimization.py:591: FutureWarning: This implementation of AdamW is deprecated and will be removed in a future version. Use the PyTorch implementation torch.optim.AdamW instead, or set `no_deprecation_warning=True` to disable this warning
  warnings.warn(
Loading `train_dataloader` to estimate number of stepping batches.
/usr/local/lib/python3.10/dist-packages/pytorch_lightning/trainer/connectors/data_connector.py:424: The 'train_dataloader' does not have many workers which may be a bottleneck. Consider increasing the value of the `num_workers` argument` to `num_workers=63` in the `DataLoader` to improve performance.

  | Name  | Type                            | Params | Mode
-----------------------------------------------------------------
0 | model | AlbertForSequenceClassification | 11.7 M | eval
-----------------------------------------------------------------
11.7 M    Trainable params
0         Non-trainable params
11.7 M    Total params
46.740    Total estimated model params size (MB)
/usr/local/lib/python3.10/dist-packages/pytorch_lightning/trainer/connectors/data_connector.py:424: The 'val_dataloader' does not have many workers which may be a bottleneck. Consider increasing the value of the `num_workers` argument` to `num_workers=63` in the `DataLoader` to improve performance.
`Trainer.fit` stopped: `max_epochs=1` reached.

MRPC

See an interactive view of the MRPC dataset in NLP Viewer

[7]:
pl.seed_everything(42)

dm = GLUEDataModule(
    model_name_or_path="distilbert-base-cased",
    task_name="mrpc",
)
dm.setup("fit")
model = GLUETransformer(
    model_name_or_path="distilbert-base-cased",
    num_labels=dm.num_labels,
    eval_splits=dm.eval_splits,
    task_name=dm.task_name,
)

trainer = pl.Trainer(
    max_epochs=3,
    accelerator="auto",
    devices=1,
)
trainer.fit(model, datamodule=dm)
Seed set to 42
/usr/local/lib/python3.10/dist-packages/transformers/tokenization_utils_base.py:2888: FutureWarning: The `pad_to_max_length` argument is deprecated and will be removed in a future version, use `padding=True` or `padding='longest'` to pad to the longest sequence in the batch, or use `padding='max_length'` to pad to a max length. In this case, you can give a specific length with `max_length` (e.g. `max_length=45`) or leave max_length to None to pad to the maximal input size of the model (e.g. 512 for Bert).
  warnings.warn(
Some weights of DistilBertForSequenceClassification were not initialized from the model checkpoint at distilbert-base-cased and are newly initialized: ['classifier.bias', 'classifier.weight', 'pre_classifier.bias', 'pre_classifier.weight']
You should probably TRAIN this model on a down-stream task to be able to use it for predictions and inference.
GPU available: True (cuda), used: True
TPU available: False, using: 0 TPU cores
HPU available: False, using: 0 HPUs
/usr/local/lib/python3.10/dist-packages/transformers/tokenization_utils_base.py:2888: FutureWarning: The `pad_to_max_length` argument is deprecated and will be removed in a future version, use `padding=True` or `padding='longest'` to pad to the longest sequence in the batch, or use `padding='max_length'` to pad to a max length. In this case, you can give a specific length with `max_length` (e.g. `max_length=45`) or leave max_length to None to pad to the maximal input size of the model (e.g. 512 for Bert).
  warnings.warn(
LOCAL_RANK: 0 - CUDA_VISIBLE_DEVICES: [0,1]
/usr/local/lib/python3.10/dist-packages/transformers/optimization.py:591: FutureWarning: This implementation of AdamW is deprecated and will be removed in a future version. Use the PyTorch implementation torch.optim.AdamW instead, or set `no_deprecation_warning=True` to disable this warning
  warnings.warn(
Loading `train_dataloader` to estimate number of stepping batches.
/usr/local/lib/python3.10/dist-packages/pytorch_lightning/trainer/connectors/data_connector.py:424: The 'train_dataloader' does not have many workers which may be a bottleneck. Consider increasing the value of the `num_workers` argument` to `num_workers=63` in the `DataLoader` to improve performance.

  | Name  | Type                                | Params | Mode
---------------------------------------------------------------------
0 | model | DistilBertForSequenceClassification | 65.8 M | eval
---------------------------------------------------------------------
65.8 M    Trainable params
0         Non-trainable params
65.8 M    Total params
263.132   Total estimated model params size (MB)
/usr/local/lib/python3.10/dist-packages/pytorch_lightning/trainer/connectors/data_connector.py:424: The 'val_dataloader' does not have many workers which may be a bottleneck. Consider increasing the value of the `num_workers` argument` to `num_workers=63` in the `DataLoader` to improve performance.
`Trainer.fit` stopped: `max_epochs=3` reached.

MNLI

  • The MNLI dataset is huge, so we aren’t going to bother trying to train on it here.

  • We will skip over training and go straight to validation.

See an interactive view of the MRPC dataset in NLP Viewer

[8]:
dm = GLUEDataModule(
    model_name_or_path="distilbert-base-cased",
    task_name="mnli",
)
dm.setup("fit")
model = GLUETransformer(
    model_name_or_path="distilbert-base-cased",
    num_labels=dm.num_labels,
    eval_splits=dm.eval_splits,
    task_name=dm.task_name,
)

trainer = pl.Trainer(
    max_epochs=3,
    accelerator="auto",
    devices=1,
)
trainer.validate(model, dm)
/usr/local/lib/python3.10/dist-packages/transformers/tokenization_utils_base.py:2888: FutureWarning: The `pad_to_max_length` argument is deprecated and will be removed in a future version, use `padding=True` or `padding='longest'` to pad to the longest sequence in the batch, or use `padding='max_length'` to pad to a max length. In this case, you can give a specific length with `max_length` (e.g. `max_length=45`) or leave max_length to None to pad to the maximal input size of the model (e.g. 512 for Bert).
  warnings.warn(
Some weights of DistilBertForSequenceClassification were not initialized from the model checkpoint at distilbert-base-cased and are newly initialized: ['classifier.bias', 'classifier.weight', 'pre_classifier.bias', 'pre_classifier.weight']
You should probably TRAIN this model on a down-stream task to be able to use it for predictions and inference.
GPU available: True (cuda), used: True
TPU available: False, using: 0 TPU cores
HPU available: False, using: 0 HPUs
/usr/local/lib/python3.10/dist-packages/transformers/tokenization_utils_base.py:2888: FutureWarning: The `pad_to_max_length` argument is deprecated and will be removed in a future version, use `padding=True` or `padding='longest'` to pad to the longest sequence in the batch, or use `padding='max_length'` to pad to a max length. In this case, you can give a specific length with `max_length` (e.g. `max_length=45`) or leave max_length to None to pad to the maximal input size of the model (e.g. 512 for Bert).
  warnings.warn(
LOCAL_RANK: 0 - CUDA_VISIBLE_DEVICES: [0,1]
/usr/local/lib/python3.10/dist-packages/pytorch_lightning/trainer/connectors/data_connector.py:424: The 'val_dataloader' does not have many workers which may be a bottleneck. Consider increasing the value of the `num_workers` argument` to `num_workers=63` in the `DataLoader` to improve performance.
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
     Validate metric           DataLoader 0             DataLoader 1
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
    accuracy_matched        0.31767702102661133      0.31767702102661133
   accuracy_mismatched      0.3187550902366638       0.3187550902366638
    val_loss_matched        1.1031880378723145       1.1031880378723145
   val_loss_mismatched      1.1027535200119019       1.1027535200119019
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
[8]:
[{'val_loss_matched': 1.1031880378723145,
  'accuracy_matched': 0.31767702102661133,
  'val_loss_mismatched': 1.1027535200119019,
  'accuracy_mismatched': 0.3187550902366638},
 {'val_loss_matched': 1.1031880378723145,
  'accuracy_matched': 0.31767702102661133,
  'val_loss_mismatched': 1.1027535200119019,
  'accuracy_mismatched': 0.3187550902366638}]

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