transformers/examples/seq2seq/finetune_trainer.py
2020-10-01 00:33:01 -04:00

420 lines
16 KiB
Python

import logging
import os
import sys
from dataclasses import dataclass, field
from typing import Callable, Dict, List, Optional, Tuple
import numpy as np
import torch
from seq2seq_trainer import Seq2SeqTrainer
from transformers import (
AutoConfig,
AutoModelForSeq2SeqLM,
AutoTokenizer,
BartTokenizer,
EvalPrediction,
HfArgumentParser,
MBartTokenizer,
T5Tokenizer,
TrainingArguments,
set_seed,
)
from transformers.modeling_bart import shift_tokens_right
from transformers.trainer_utils import EvaluationStrategy
from utils import (
LegacySeq2SeqDataset,
Seq2SeqDataset,
assert_all_frozen,
calculate_bleu,
calculate_rouge,
freeze_embeds,
freeze_params,
lmap,
save_json,
trim_batch,
use_task_specific_params,
write_txt_file,
)
logger = logging.getLogger(__name__)
class Seq2SeqDataCollator:
def __init__(self, tokenizer, data_args, tpu_num_cores=None):
self.tokenizer = tokenizer
self.pad_token_id = tokenizer.pad_token_id
assert self.pad_token_id is not None, "self.pad_token_id must be defined"
self.data_args = data_args
self.tpu_num_cores = tpu_num_cores
self.add_prefix_space = isinstance(tokenizer, BartTokenizer)
def __call__(self, batch) -> Dict[str, torch.Tensor]:
if hasattr(self.tokenizer, "prepare_seq2seq_batch"):
batch = self._encode(batch)
input_ids, attention_mask, labels = (
batch["input_ids"],
batch["attention_mask"],
batch["labels"],
)
else:
input_ids = torch.stack([x["input_ids"] for x in batch])
attention_mask = torch.stack([x["attention_mask"] for x in batch])
labels = torch.stack([x["labels"] for x in batch])
labels = trim_batch(labels, self.pad_token_id)
input_ids, attention_mask = trim_batch(input_ids, self.pad_token_id, attention_mask=attention_mask)
if isinstance(self.tokenizer, T5Tokenizer):
decoder_input_ids = self._shift_right_t5(labels)
else:
decoder_input_ids = shift_tokens_right(labels, self.pad_token_id)
batch = {
"input_ids": input_ids,
"attention_mask": attention_mask,
"decoder_input_ids": decoder_input_ids,
"labels": labels,
}
return batch
def _shift_right_t5(self, input_ids):
# shift inputs to the right
shifted_input_ids = input_ids.new_zeros(input_ids.shape)
shifted_input_ids[..., 1:] = input_ids[..., :-1].clone()
shifted_input_ids[..., 0] = self.pad_token_id
return shifted_input_ids
def _encode(self, batch) -> Dict[str, torch.Tensor]:
batch_encoding = self.tokenizer.prepare_seq2seq_batch(
[x["src_texts"] for x in batch],
src_lang=self.data_args.src_lang,
tgt_texts=[x["tgt_texts"] for x in batch],
tgt_lang=self.data_args.tgt_lang,
max_length=self.data_args.max_source_length,
max_target_length=self.data_args.max_target_length,
padding="max_length" if self.tpu_num_cores is not None else "longest", # TPU hack
return_tensors="pt",
add_prefix_space=self.add_prefix_space,
)
return batch_encoding.data
@dataclass
class Seq2SeqTrainingArguments(TrainingArguments):
"""
Parameters:
label_smoothing (:obj:`float`, `optional`, defaults to 0):
The label smoothing epsilon to apply (if not zero).
sortish_sampler (:obj:`bool`, `optional`, defaults to :obj:`False`):
Whether to SortishSamler or not. It sorts the inputs according to lenghts in-order to minimizing the padding size.
predict_with_generate (:obj:`bool`, `optional`, defaults to :obj:`False`):
Whether to use generate to calculate generative metrics (ROUGE, BLEU).
"""
label_smoothing: Optional[float] = field(
default=0.0, metadata={"help": "The label smoothing epsilon to apply (if not zero)."}
)
sortish_sampler: bool = field(default=False, metadata={"help": "Whether to SortishSamler or not."})
predict_with_generate: bool = field(
default=False, metadata={"help": "Whether to use generate to calculate generative metrics (ROUGE, BLEU)."}
)
@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"}
)
cache_dir: Optional[str] = field(
default=None, metadata={"help": "Where do you want to store the pretrained models downloaded from s3"}
)
freeze_encoder: bool = field(default=False, metadata={"help": "Whether tp freeze the encoder."})
freeze_embeds: bool = field(default=False, metadata={"help": "Whether to freeze the embeddings."})
@dataclass
class DataTrainingArguments:
"""
Arguments pertaining to what data we are going to input our model for training and eval.
"""
data_dir: str = field(
metadata={"help": "The input data dir. Should contain the .tsv files (or other data files) for the task."}
)
task: Optional[str] = field(
default="summarization",
metadata={"help": "Task name, summarization (or summarization_{dataset} for pegasus) or translation"},
)
max_source_length: Optional[int] = field(
default=1024,
metadata={
"help": "The maximum total input sequence length after tokenization. Sequences longer "
"than this will be truncated, sequences shorter will be padded."
},
)
max_target_length: Optional[int] = field(
default=128,
metadata={
"help": "The maximum total sequence length for target text after tokenization. Sequences longer "
"than this will be truncated, sequences shorter will be padded."
},
)
val_max_target_length: Optional[int] = field(
default=142,
metadata={
"help": "The maximum total sequence length for validation target text after tokenization. Sequences longer "
"than this will be truncated, sequences shorter will be padded."
},
)
test_max_target_length: Optional[int] = field(
default=142,
metadata={
"help": "The maximum total sequence length for test target text after tokenization. Sequences longer "
"than this will be truncated, sequences shorter will be padded."
},
)
n_train: Optional[int] = field(default=-1, metadata={"help": "# training examples. -1 means use all."})
n_val: Optional[int] = field(default=-1, metadata={"help": "# validation examples. -1 means use all."})
n_test: Optional[int] = field(default=-1, metadata={"help": "# test examples. -1 means use all."})
src_lang: Optional[str] = field(default=None, metadata={"help": "Source language id for translation."})
tgt_lang: Optional[str] = field(default=None, metadata={"help": "Target language id for translation."})
eval_beams: Optional[int] = field(default=None, metadata={"help": "# num_beams to use for evaluation."})
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, Seq2SeqTrainingArguments))
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)
# Set seed
set_seed(training_args.seed)
# 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 = AutoModelForSeq2SeqLM.from_pretrained(
model_args.model_name_or_path,
from_tf=".ckpt" in model_args.model_name_or_path,
config=config,
cache_dir=model_args.cache_dir,
)
# use task specific params
use_task_specific_params(model, data_args.task)
# set num_beams for evaluation
if data_args.eval_beams is None:
data_args.eval_beams = model.config.num_beams
# set decoder_start_token_id for MBart
if model.config.decoder_start_token_id is None and isinstance(tokenizer, MBartTokenizer):
assert (
data_args.tgt_lang is not None and data_args.src_lang is not None
), "mBart requires --tgt_lang and --src_lang"
model.config.decoder_start_token_id = tokenizer.lang_code_to_id[data_args.tgt_lang]
def build_compute_metrics_fn(task_name: str) -> Callable[[EvalPrediction], Dict]:
def non_pad_len(tokens: np.ndarray) -> int:
return np.count_nonzero(tokens != tokenizer.pad_token_id)
def decode_pred(pred: EvalPrediction) -> Tuple[List[str], List[str]]:
pred_str = tokenizer.batch_decode(pred.predictions, skip_special_tokens=True)
label_str = tokenizer.batch_decode(pred.label_ids, skip_special_tokens=True)
pred_str = lmap(str.strip, pred_str)
label_str = lmap(str.strip, label_str)
return pred_str, label_str
def summarization_metrics(pred: EvalPrediction) -> Dict:
pred_str, label_str = decode_pred(pred)
rouge: Dict = calculate_rouge(pred_str, label_str)
summ_len = np.round(np.mean(lmap(non_pad_len, pred.predictions)), 1)
rouge.update({"gen_len": summ_len})
return rouge
def translation_metrics(pred: EvalPrediction) -> Dict:
pred_str, label_str = decode_pred(pred)
bleu: Dict = calculate_bleu(pred_str, label_str)
gen_len = np.round(np.mean(lmap(non_pad_len, pred.predictions)), 1)
bleu.update({"gen_len": gen_len})
return bleu
compute_metrics_fn = summarization_metrics if "summarization" in task_name else translation_metrics
return compute_metrics_fn
if model_args.freeze_embeds:
freeze_embeds(model)
if model_args.freeze_encoder:
freeze_params(model.get_encoder())
assert_all_frozen(model.get_encoder())
dataset_class = Seq2SeqDataset if hasattr(tokenizer, "prepare_seq2seq_batch") else LegacySeq2SeqDataset
# Get datasets
train_dataset = (
dataset_class(
tokenizer,
type_path="train",
data_dir=data_args.data_dir,
n_obs=data_args.n_train,
max_target_length=data_args.max_target_length,
max_source_length=data_args.max_source_length,
prefix=model.config.prefix or "",
)
if training_args.do_train
else None
)
eval_dataset = (
dataset_class(
tokenizer,
type_path="val",
data_dir=data_args.data_dir,
n_obs=data_args.n_val,
max_target_length=data_args.val_max_target_length,
max_source_length=data_args.max_source_length,
prefix=model.config.prefix or "",
)
if training_args.do_eval or training_args.evaluation_strategy != EvaluationStrategy.NO
else None
)
test_dataset = (
dataset_class(
tokenizer,
type_path="test",
data_dir=data_args.data_dir,
n_obs=data_args.n_test,
max_target_length=data_args.test_max_target_length,
max_source_length=data_args.max_source_length,
prefix=model.config.prefix or "",
)
if training_args.do_predict
else None
)
# Initialize our Trainer
trainer = Seq2SeqTrainer(
model=model,
args=training_args,
train_dataset=train_dataset,
eval_dataset=eval_dataset,
data_collator=Seq2SeqDataCollator(tokenizer, data_args, training_args.tpu_num_cores),
compute_metrics=build_compute_metrics_fn(data_args.task) if training_args.predict_with_generate else None,
data_args=data_args,
)
# 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_process_zero():
tokenizer.save_pretrained(training_args.output_dir)
# Evaluation
eval_results = {}
if training_args.do_eval:
logger.info("*** Evaluate ***")
result = trainer.evaluate()
if trainer.is_world_process_zero():
logger.info("***** Eval results *****")
for key, value in result.items():
logger.info(" %s = %s", key, value)
save_json(result, os.path.join(training_args.output_dir, "eval_results.json"))
eval_results.update(result)
if training_args.do_predict:
logging.info("*** Test ***")
test_output = trainer.predict(test_dataset=test_dataset)
test_metrics = {k.replace("eval", "test"): v for k, v in test_output.metrics.items()}
if trainer.is_world_process_zero():
logger.info("***** Test results *****")
for key, value in test_metrics.items():
logger.info(" %s = %s", key, value)
save_json(test_metrics, os.path.join(training_args.output_dir, "test_results.json"))
eval_results.update(test_metrics)
if training_args.predict_with_generate:
test_preds = tokenizer.batch_decode(
test_output.predictions, skip_special_tokens=True, clean_up_tokenization_spaces=True
)
test_preds = lmap(str.strip, test_preds)
write_txt_file(test_preds, os.path.join(training_args.output_dir, "test_generations.txt"))
if trainer.is_world_process_zero():
save_json(eval_results, "all_results.json")
return eval_results
def _mp_fn(index):
# For xla_spawn (TPUs)
main()
if __name__ == "__main__":
main()