examples/seq2seq supports translation (#5202)

This commit is contained in:
Sam Shleifer
2020-06-24 23:58:11 -04:00
committed by GitHub
parent d12ceb48ba
commit 40457bcebb
32 changed files with 626 additions and 636 deletions

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import argparse
import glob
import logging
import os
import time
from collections import defaultdict
from pathlib import Path
from typing import Dict, List, Tuple
import numpy as np
import pytorch_lightning as pl
import torch
from torch.utils.data import DataLoader
from lightning_base import BaseTransformer, add_generic_args, generic_train
from transformers import get_linear_schedule_with_warmup
try:
from .utils import (
use_task_specific_params,
SummarizationDataset,
lmap,
flatten_list,
pickle_save,
save_git_info,
save_json,
freeze_params,
calculate_rouge,
get_git_info,
ROUGE_KEYS,
calculate_bleu_score,
)
from .callbacks import Seq2SeqLoggingCallback, get_checkpoint_callback
except ImportError:
from utils import (
use_task_specific_params,
SummarizationDataset,
lmap,
flatten_list,
pickle_save,
save_git_info,
save_json,
freeze_params,
calculate_rouge,
get_git_info,
ROUGE_KEYS,
calculate_bleu_score,
)
from callbacks import Seq2SeqLoggingCallback, get_checkpoint_callback
logger = logging.getLogger(__name__)
class SummarizationModule(BaseTransformer):
mode = "summarization"
loss_names = ["loss"]
metric_names = ROUGE_KEYS
val_metric = "rouge2"
def __init__(self, hparams, **kwargs):
super().__init__(hparams, num_labels=None, mode=self.mode, **kwargs)
use_task_specific_params(self.model, "summarization")
save_git_info(self.hparams.output_dir)
self.metrics_save_path = Path(self.output_dir) / "metrics.json"
self.hparams_save_path = Path(self.output_dir) / "hparams.pkl"
pickle_save(self.hparams, self.hparams_save_path)
self.step_count = 0
self.metrics = defaultdict(list)
self.dataset_kwargs: dict = dict(
data_dir=self.hparams.data_dir,
max_source_length=self.hparams.max_source_length,
prefix=self.model.config.prefix or "",
)
n_observations_per_split = {
"train": self.hparams.n_train,
"val": self.hparams.n_val,
"test": self.hparams.n_test,
}
self.n_obs = {k: v if v >= 0 else None for k, v in n_observations_per_split.items()}
self.target_lens = {
"train": self.hparams.max_target_length,
"val": self.hparams.val_max_target_length,
"test": self.hparams.test_max_target_length,
}
assert self.target_lens["train"] <= self.target_lens["val"], f"target_lens: {self.target_lens}"
assert self.target_lens["train"] <= self.target_lens["test"], f"target_lens: {self.target_lens}"
if self.hparams.freeze_embeds:
self.freeze_embeds()
if self.hparams.freeze_encoder:
freeze_params(self.model.model.encoder) # TODO: this will break for t5
self.hparams.git_sha = get_git_info()["repo_sha"]
self.num_workers = hparams.num_workers
def freeze_embeds(self):
"""Freeze token embeddings and positional embeddings for bart, just token embeddings for t5."""
try:
freeze_params(self.model.model.shared)
for d in [self.model.model.encoder, self.model.model.decoder]:
freeze_params(d.embed_positions)
freeze_params(d.embed_tokens)
except AttributeError:
freeze_params(self.model.shared)
for d in [self.model.encoder, self.model.decoder]:
freeze_params(d.embed_tokens)
def forward(self, input_ids, **kwargs):
return self.model(input_ids, **kwargs)
def ids_to_clean_text(self, generated_ids: List[int]):
gen_text = self.tokenizer.batch_decode(
generated_ids, skip_special_tokens=True, clean_up_tokenization_spaces=True
)
return lmap(str.strip, gen_text)
def _step(self, batch: dict) -> Tuple:
pad_token_id = self.tokenizer.pad_token_id
source_ids, source_mask, y = batch["input_ids"], batch["attention_mask"], batch["decoder_input_ids"]
y_ids = y[:, :-1].contiguous()
lm_labels = y[:, 1:].clone()
lm_labels[y[:, 1:] == pad_token_id] = -100
outputs = self(source_ids, attention_mask=source_mask, decoder_input_ids=y_ids, labels=lm_labels,)
loss = outputs[0]
return (loss,)
def training_step(self, batch, batch_idx) -> Dict:
loss_tensors = self._step(batch)
logs = {name: loss for name, loss in zip(self.loss_names, loss_tensors)}
return {"loss": loss_tensors[0], "log": logs}
def validation_step(self, batch, batch_idx) -> Dict:
return self._generative_step(batch)
def validation_epoch_end(self, outputs, prefix="val") -> Dict:
self.step_count += 1
losses = {k: torch.stack([x[k] for x in outputs]).mean() for k in self.loss_names}
loss = losses["loss"]
rouges = {k: np.array([x[k] for x in outputs]).mean() for k in self.metric_names + ["gen_time", "summ_len"]}
rouge_tensor: torch.FloatTensor = torch.tensor(rouges[self.val_metric]).type_as(loss)
rouges.update({k: v.item() for k, v in losses.items()})
losses.update(rouges)
metrics = {f"{prefix}_avg_{k}": x for k, x in losses.items()}
metrics["step_count"] = self.step_count
self.save_metrics(metrics, prefix) # writes to self.metrics_save_path
preds = flatten_list([x["preds"] for x in outputs])
return {"log": metrics, "preds": preds, f"{prefix}_loss": loss, f"{prefix}_{self.val_metric}": rouge_tensor}
def save_metrics(self, latest_metrics, type_path) -> None:
self.metrics[type_path].append(latest_metrics)
save_json(self.metrics, self.metrics_save_path)
def calc_generative_metrics(self, preds, target) -> Dict:
return calculate_rouge(preds, target)
def _generative_step(self, batch: dict) -> dict:
pad_token_id = self.tokenizer.pad_token_id
source_ids, source_mask, y = SummarizationDataset.trim_seq2seq_batch(batch, pad_token_id)
t0 = time.time()
generated_ids = self.model.generate(input_ids=source_ids, attention_mask=source_mask, use_cache=True,)
gen_time = (time.time() - t0) / source_ids.shape[0]
preds = self.ids_to_clean_text(generated_ids)
target = self.ids_to_clean_text(y)
loss_tensors = self._step(batch)
base_metrics = {name: loss for name, loss in zip(self.loss_names, loss_tensors)}
rouge: Dict = self.calc_generative_metrics(preds, target)
summ_len = np.mean(lmap(len, generated_ids))
base_metrics.update(gen_time=gen_time, summ_len=summ_len, preds=preds, target=target, **rouge)
return base_metrics
def test_step(self, batch, batch_idx):
return self._generative_step(batch)
def test_epoch_end(self, outputs):
return self.validation_epoch_end(outputs, prefix="test")
def get_dataset(self, type_path) -> SummarizationDataset:
n_obs = self.n_obs[type_path]
max_target_length = self.target_lens[type_path]
dataset = SummarizationDataset(
self.tokenizer,
type_path=type_path,
n_obs=n_obs,
max_target_length=max_target_length,
**self.dataset_kwargs,
)
return dataset
def get_dataloader(self, type_path: str, batch_size: int, shuffle: bool = False) -> DataLoader:
dataset = self.get_dataset(type_path)
sampler = None
if self.hparams.sortish_sampler and type_path == "train":
assert self.hparams.gpus <= 1 # TODO: assert earlier
sampler = dataset.make_sortish_sampler(batch_size)
shuffle = False
dataloader = DataLoader(
dataset,
batch_size=batch_size,
collate_fn=dataset.collate_fn,
shuffle=shuffle,
num_workers=self.num_workers,
sampler=sampler,
)
return dataloader
def train_dataloader(self) -> DataLoader:
dataloader = self.get_dataloader("train", batch_size=self.hparams.train_batch_size, shuffle=True)
t_total = (
(len(dataloader.dataset) // (self.hparams.train_batch_size * max(1, self.hparams.gpus)))
// self.hparams.gradient_accumulation_steps
* float(self.hparams.num_train_epochs)
)
scheduler = get_linear_schedule_with_warmup(
self.opt, num_warmup_steps=self.hparams.warmup_steps, num_training_steps=t_total
)
self.lr_scheduler = scheduler
return dataloader
def val_dataloader(self) -> DataLoader:
return self.get_dataloader("val", batch_size=self.hparams.eval_batch_size)
def test_dataloader(self) -> DataLoader:
return self.get_dataloader("test", batch_size=self.hparams.eval_batch_size)
@staticmethod
def add_model_specific_args(parser, root_dir):
BaseTransformer.add_model_specific_args(parser, root_dir)
add_generic_args(parser, root_dir)
parser.add_argument(
"--max_source_length",
default=1024,
type=int,
help="The maximum total input sequence length after tokenization. Sequences longer "
"than this will be truncated, sequences shorter will be padded.",
)
parser.add_argument(
"--max_target_length",
default=56,
type=int,
help="The maximum total input sequence length after tokenization. Sequences longer "
"than this will be truncated, sequences shorter will be padded.",
)
parser.add_argument(
"--val_max_target_length",
default=142, # these defaults are optimized for CNNDM. For xsum, see README.md.
type=int,
help="The maximum total input sequence length after tokenization. Sequences longer "
"than this will be truncated, sequences shorter will be padded.",
)
parser.add_argument(
"--test_max_target_length",
default=142,
type=int,
help="The maximum total input sequence length after tokenization. Sequences longer "
"than this will be truncated, sequences shorter will be padded.",
)
parser.add_argument(
"--data_dir",
type=str,
required=True,
help="The input data dir. Should contain train.source, train.target, val.source, val.target, test.source, test.target",
)
parser.add_argument("--freeze_encoder", action="store_true")
parser.add_argument("--freeze_embeds", action="store_true")
parser.add_argument("--sortish_sampler", action="store_true", default=False)
parser.add_argument("--logger", type=str, choices=["default", "wandb", "wandb_shared"], default="default")
parser.add_argument("--n_train", type=int, default=-1, required=False, help="# examples. -1 means use all.")
parser.add_argument("--n_val", type=int, default=500, required=False, help="# examples. -1 means use all.")
parser.add_argument("--n_test", type=int, default=-1, required=False, help="# examples. -1 means use all.")
parser.add_argument(
"--task", type=str, default="summarization", required=False, help="# examples. -1 means use all."
)
return parser
class TranslationModule(SummarizationModule):
mode = "translation"
loss_names = ["loss"]
metric_names = ["bleu"]
val_metric = "bleu"
def calc_generative_metrics(self, preds, target) -> dict:
return calculate_bleu_score(preds, target)
def main(args, model=None) -> SummarizationModule:
Path(args.output_dir).mkdir(exist_ok=True)
if len(os.listdir(args.output_dir)) > 3 and args.do_train:
raise ValueError("Output directory ({}) already exists and is not empty.".format(args.output_dir))
if model is None:
if args.task == "summarization":
model: SummarizationModule = SummarizationModule(args)
else:
model: SummarizationModule = TranslationModule(args)
dataset = Path(args.data_dir).name
if (
args.logger == "default"
or args.fast_dev_run
or str(args.output_dir).startswith("/tmp")
or str(args.output_dir).startswith("/var")
):
logger = True # don't pollute wandb logs unnecessarily
elif args.logger == "wandb":
from pytorch_lightning.loggers import WandbLogger
logger = WandbLogger(name=model.output_dir.name, project=dataset)
elif args.logger == "wandb_shared":
from pytorch_lightning.loggers import WandbLogger
logger = WandbLogger(name=model.output_dir.name, project=f"hf_{dataset}")
trainer: pl.Trainer = generic_train(
model,
args,
logging_callback=Seq2SeqLoggingCallback(),
checkpoint_callback=get_checkpoint_callback(args.output_dir, model.val_metric),
logger=logger,
# TODO: early stopping callback seems messed up
)
pickle_save(model.hparams, model.output_dir / "hparams.pkl")
if not args.do_predict:
return model
model.hparams.test_checkpoint = ""
checkpoints = list(sorted(glob.glob(os.path.join(args.output_dir, "*.ckpt"), recursive=True)))
if checkpoints:
model.hparams.test_checkpoint = checkpoints[-1]
trainer.resume_from_checkpoint = checkpoints[-1]
trainer.logger.log_hyperparams(model.hparams)
trainer.test(model) # this breaks in DDP, known lightning issue. See evaluate_checkpoint to recover metrics.
return model
if __name__ == "__main__":
parser = argparse.ArgumentParser()
parser = SummarizationModule.add_model_specific_args(parser, os.getcwd())
args = parser.parse_args()
main(args)