Add beam search
This commit is contained in:
committed by
Julien Chaumond
parent
1c71ecc880
commit
9660ba1cbd
@@ -1,502 +0,0 @@
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# coding=utf-8
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# Copyright 2019 The HuggingFace Inc. team.
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# Copyright (c) 2019 The HuggingFace Inc. All rights reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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""" Finetuning seq2seq models for sequence generation."""
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import argparse
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import functools
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import logging
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import os
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import random
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import sys
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import numpy as np
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from tqdm import tqdm, trange
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import torch
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from torch.optim import Adam
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from torch.utils.data import DataLoader, RandomSampler, SequentialSampler
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from transformers import (
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AutoTokenizer,
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BertForMaskedLM,
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BertConfig,
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PreTrainedEncoderDecoder,
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Model2Model,
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)
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from utils_summarization import (
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CNNDailyMailDataset,
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encode_for_summarization,
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fit_to_block_size,
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build_lm_labels,
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build_mask,
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compute_token_type_ids,
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)
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logger = logging.getLogger(__name__)
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logging.basicConfig(stream=sys.stdout, level=logging.INFO)
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def set_seed(args):
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random.seed(args.seed)
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np.random.seed(args.seed)
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torch.manual_seed(args.seed)
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# ------------
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# Load dataset
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# ------------
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def load_and_cache_examples(args, tokenizer):
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dataset = CNNDailyMailDataset(tokenizer, data_dir=args.data_dir)
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return dataset
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def collate(data, tokenizer, block_size):
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""" List of tuple as an input. """
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# remove the files with empty an story/summary, encode and fit to block
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data = filter(lambda x: not (len(x[0]) == 0 or len(x[1]) == 0), data)
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data = [
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encode_for_summarization(story, summary, tokenizer) for story, summary in data
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]
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data = [
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(
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fit_to_block_size(story, block_size, tokenizer.pad_token_id),
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fit_to_block_size(summary, block_size, tokenizer.pad_token_id),
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)
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for story, summary in data
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]
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stories = torch.tensor([story for story, summary in data])
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summaries = torch.tensor([summary for story, summary in data])
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encoder_token_type_ids = compute_token_type_ids(stories, tokenizer.cls_token_id)
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encoder_mask = build_mask(stories, tokenizer.pad_token_id)
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decoder_mask = build_mask(summaries, tokenizer.pad_token_id)
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lm_labels = build_lm_labels(summaries, tokenizer.pad_token_id)
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return (
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stories,
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summaries,
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encoder_token_type_ids,
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encoder_mask,
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decoder_mask,
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lm_labels,
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)
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# ----------
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# Optimizers
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# ----------
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class BertSumOptimizer(object):
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""" Specific optimizer for BertSum.
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As described in [1], the authors fine-tune BertSum for abstractive
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summarization using two Adam Optimizers with different warm-up steps and
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learning rate. They also use a custom learning rate scheduler.
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[1] Liu, Yang, and Mirella Lapata. "Text summarization with pretrained encoders."
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arXiv preprint arXiv:1908.08345 (2019).
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"""
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def __init__(self, model, lr, warmup_steps, beta_1=0.99, beta_2=0.999, eps=1e-8):
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self.encoder = model.encoder
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self.decoder = model.decoder
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self.lr = lr
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self.warmup_steps = warmup_steps
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self.optimizers = {
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"encoder": Adam(
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model.encoder.parameters(),
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lr=lr["encoder"],
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betas=(beta_1, beta_2),
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eps=eps,
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),
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"decoder": Adam(
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model.decoder.parameters(),
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lr=lr["decoder"],
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betas=(beta_1, beta_2),
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eps=eps,
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),
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}
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self._step = 0
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def _update_rate(self, stack):
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return self.lr[stack] * min(
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self._step ** (-0.5), self._step * self.warmup_steps[stack] ** (-0.5)
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)
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def zero_grad(self):
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self.optimizer_decoder.zero_grad()
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self.optimizer_encoder.zero_grad()
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def step(self):
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self._step += 1
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for stack, optimizer in self.optimizers.items():
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new_rate = self._update_rate(stack)
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for param_group in optimizer.param_groups:
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param_group["lr"] = new_rate
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optimizer.step()
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# ------------
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# Train
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# ------------
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def train(args, model, tokenizer):
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""" Fine-tune the pretrained model on the corpus. """
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set_seed(args)
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# Load the data
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args.train_batch_size = args.per_gpu_train_batch_size * max(1, args.n_gpu)
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train_dataset = load_and_cache_examples(args, tokenizer)
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train_sampler = RandomSampler(train_dataset)
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model_collate_fn = functools.partial(collate, tokenizer=tokenizer, block_size=512)
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train_dataloader = DataLoader(
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train_dataset,
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sampler=train_sampler,
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batch_size=args.train_batch_size,
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collate_fn=model_collate_fn,
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)
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# Training schedule
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if args.max_steps > 0:
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t_total = args.max_steps
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args.num_train_epochs = t_total // (
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len(train_dataloader) // args.gradient_accumulation_steps + 1
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)
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else:
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t_total = (
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len(train_dataloader)
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// args.gradient_accumulation_steps
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* args.num_train_epochs
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)
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# Prepare the optimizer
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lr = {"encoder": 0.002, "decoder": 0.2}
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warmup_steps = {"encoder": 20000, "decoder": 10000}
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optimizer = BertSumOptimizer(model, lr, warmup_steps)
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# Train
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logger.info("***** Running training *****")
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logger.info(" Num examples = %d", len(train_dataset))
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logger.info(" Num Epochs = %d", args.num_train_epochs)
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logger.info(
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" Instantaneous batch size per GPU = %d", args.per_gpu_train_batch_size
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)
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logger.info(
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" Total train batch size (w. parallel, distributed & accumulation) = %d",
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args.train_batch_size * args.gradient_accumulation_steps
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# * (torch.distributed.get_world_size() if args.local_rank != -1 else 1),
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)
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logger.info(" Gradient Accumulation steps = %d", args.gradient_accumulation_steps)
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logger.info(" Total optimization steps = %d", t_total)
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model.zero_grad()
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train_iterator = trange(args.num_train_epochs, desc="Epoch", disable=True)
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global_step = 0
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tr_loss = 0.0
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for _ in train_iterator:
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epoch_iterator = tqdm(train_dataloader, desc="Iteration", disable=True)
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for step, batch in enumerate(epoch_iterator):
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source, target, encoder_token_type_ids, encoder_mask, decoder_mask, lm_labels = batch
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source = source.to(args.device)
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target = target.to(args.device)
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encoder_token_type_ids = encoder_token_type_ids.to(args.device)
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encoder_mask = encoder_mask.to(args.device)
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decoder_mask = decoder_mask.to(args.device)
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lm_labels = lm_labels.to(args.device)
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model.train()
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outputs = model(
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source,
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target,
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encoder_token_type_ids=encoder_token_type_ids,
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encoder_attention_mask=encoder_mask,
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decoder_attention_mask=decoder_mask,
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decoder_lm_labels=lm_labels,
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)
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loss = outputs[0]
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print(loss)
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if args.gradient_accumulation_steps > 1:
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loss /= args.gradient_accumulation_steps
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loss.backward()
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tr_loss += loss.item()
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if (step + 1) % args.gradient_accumulation_steps == 0:
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torch.nn.utils.clip_grad_norm_(model.parameters(), args.max_grad_norm)
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optimizer.step()
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model.zero_grad()
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global_step += 1
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if args.max_steps > 0 and global_step > args.max_steps:
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epoch_iterator.close()
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break
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if args.max_steps > 0 and global_step > args.max_steps:
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train_iterator.close()
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break
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return global_step, tr_loss / global_step
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# ------------
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# Train
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# ------------
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def evaluate(args, model, tokenizer, prefix=""):
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set_seed(args)
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args.eval_batch_size = args.per_gpu_eval_batch_size * max(1, args.n_gpu)
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eval_dataset = load_and_cache_examples(args, tokenizer, evaluate=True)
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eval_sampler = SequentialSampler(eval_dataset)
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eval_dataloader = DataLoader(
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eval_dataset, sampler=eval_sampler, batch_size=args.eval_batch_size
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)
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# multi-gpu evaluate
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if args.n_gpu > 1:
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model = torch.nn.DataParallel(model)
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logger.info("***** Running evaluation {} *****".format(prefix))
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logger.info(" Num examples = %d", len(eval_dataset))
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logger.info(" Batch size = %d", args.eval_batch_size)
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eval_loss = 0.0
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nb_eval_steps = 0
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model.eval()
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for batch in tqdm(eval_dataloader, desc="Evaluating"):
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source, target, encoder_token_type_ids, encoder_mask, decoder_mask, lm_labels = batch
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source = source.to(args.device)
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target = target.to(args.device)
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encoder_token_type_ids = encoder_token_type_ids.to(args.device)
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encoder_mask = encoder_mask.to(args.device)
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decoder_mask = decoder_mask.to(args.device)
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lm_labels = lm_labels.to(args.device)
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with torch.no_grad():
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outputs = model(
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source,
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target,
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encoder_token_type_ids=encoder_token_type_ids,
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encoder_attention_mask=encoder_mask,
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decoder_attention_mask=decoder_mask,
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decoder_lm_labels=lm_labels,
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)
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lm_loss = outputs[0]
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eval_loss += lm_loss.mean().item()
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nb_eval_steps += 1
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eval_loss = eval_loss / nb_eval_steps
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perplexity = torch.exp(torch.tensor(eval_loss))
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result = {"perplexity": perplexity}
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# Save the evaluation's results
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output_eval_file = os.path.join(args.output_dir, "eval_results.txt")
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if not os.path.exists(args.output_dir):
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os.makedirs(args.output_dir)
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with open(output_eval_file, "w") as writer:
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logger.info("***** Eval results {} *****".format(prefix))
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for key in sorted(result.keys()):
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logger.info(" %s = %s", key, str(result[key]))
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writer.write("%s = %s\n" % (key, str(result[key])))
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return result
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def save_model_checkpoints(args, model, tokenizer):
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if not os.path.exists(args.output_dir):
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os.makedirs(args.output_dir)
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logger.info("Saving model checkpoint to %s", args.output_dir)
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# Save a trained model, configuration and tokenizer using `save_pretrained()`.
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# They can then be reloaded using `from_pretrained()`
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model_to_save = (
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model.module if hasattr(model, "module") else model
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) # Take care of distributed/parallel training
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model_to_save.save_pretrained(args.output_dir, model_type='bert')
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tokenizer.save_pretrained(args.output_dir)
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torch.save(args, os.path.join(args.output_dir, "training_arguments.bin"))
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def main():
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parser = argparse.ArgumentParser()
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# Required parameters
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parser.add_argument(
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"--data_dir",
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default=None,
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type=str,
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required=True,
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help="The input training data file (a text file).",
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)
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parser.add_argument(
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"--output_dir",
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default=None,
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type=str,
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required=True,
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help="The output directory where the model predictions and checkpoints will be written.",
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)
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# Optional parameters
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parser.add_argument(
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"--gradient_accumulation_steps",
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type=int,
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default=1,
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help="Number of updates steps to accumulate before performing a backward/update pass.",
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)
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parser.add_argument(
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"--do_evaluate",
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type=bool,
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default=False,
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help="Run model evaluation on out-of-sample data.",
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)
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parser.add_argument("--do_train", type=bool, default=False, help="Run training.")
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parser.add_argument(
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"--do_overwrite_output_dir",
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type=bool,
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default=False,
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help="Whether to overwrite the output dir.",
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)
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parser.add_argument(
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"--model_name_or_path",
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default="bert-base-cased",
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type=str,
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help="The model checkpoint to initialize the encoder and decoder's weights with.",
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)
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parser.add_argument(
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"--model_type",
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default="bert",
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type=str,
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help="The decoder architecture to be fine-tuned.",
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)
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parser.add_argument(
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"--max_grad_norm", default=1.0, type=float, help="Max gradient norm."
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)
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parser.add_argument(
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"--max_steps",
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default=-1,
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type=int,
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help="If > 0: set total number of training steps to perform. Override num_train_epochs.",
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)
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parser.add_argument(
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"--to_cpu", default=False, type=bool, help="Whether to force training on CPU."
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)
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parser.add_argument(
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"--num_train_epochs",
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default=10,
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type=int,
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help="Total number of training epochs to perform.",
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)
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parser.add_argument(
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"--per_gpu_train_batch_size",
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default=4,
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type=int,
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help="Batch size per GPU/CPU for training.",
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)
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parser.add_argument("--seed", default=42, type=int)
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args = parser.parse_args()
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if (
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os.path.exists(args.output_dir)
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and os.listdir(args.output_dir)
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and args.do_train
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and not args.do_overwrite_output_dir
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):
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raise ValueError(
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"Output directory ({}) already exists and is not empty. Use --do_overwrite_output_dir to overwrite.".format(
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args.output_dir
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)
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)
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# Set up training device
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if args.to_cpu or not torch.cuda.is_available():
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args.device = torch.device("cpu")
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args.n_gpu = 0
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else:
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args.device = torch.device("cuda")
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args.n_gpu = torch.cuda.device_count()
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# Load pretrained model and tokenizer. The decoder's weights are randomly initialized.
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tokenizer = AutoTokenizer.from_pretrained(args.model_name_or_path)
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config = BertConfig.from_pretrained(args.model_name_or_path)
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decoder_model = BertForMaskedLM(config)
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model = Model2Model.from_pretrained(
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args.model_name_or_path, decoder_model=decoder_model
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)
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# Setup logging
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logging.basicConfig(
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format="%(asctime)s - %(levelname)s - %(name)s - %(message)s",
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datefmt="%m/%d/%Y %H:%M:%S",
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level=logging.INFO,
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)
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logger.warning(
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"Process rank: %s, device: %s, n_gpu: %s, distributed training: %s, 16-bits training: %s",
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0,
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args.device,
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args.n_gpu,
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False,
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False,
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)
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logger.info("Training/evaluation parameters %s", args)
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# Train the model
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model.to(args.device)
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if args.do_train:
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try:
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global_step, tr_loss = train(args, model, tokenizer)
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except KeyboardInterrupt:
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response = input("You interrupted the training. Do you want to save the model checkpoints? [Y/n]")
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if response.lower() in ["", "y", "yes"]:
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save_model_checkpoints(args, model, tokenizer)
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sys.exit(0)
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logger.info(" global_step = %s, average loss = %s", global_step, tr_loss)
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save_model_checkpoints(args, model, tokenizer)
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# Evaluate the model
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results = {}
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if args.do_evaluate:
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checkpoints = [args.output_dir]
|
||||
logger.info("Evaluate the following checkpoints: %s", checkpoints)
|
||||
for checkpoint in checkpoints:
|
||||
encoder_checkpoint = os.path.join(checkpoint, "bert_encoder")
|
||||
decoder_checkpoint = os.path.join(checkpoint, "bert_decoder")
|
||||
model = PreTrainedEncoderDecoder.from_pretrained(
|
||||
encoder_checkpoint, decoder_checkpoint
|
||||
)
|
||||
model.to(args.device)
|
||||
print("model loaded")
|
||||
|
||||
return results
|
||||
|
||||
|
||||
if __name__ == "__main__":
|
||||
main()
|
||||
@@ -25,9 +25,8 @@ class CNNDailyMailDataset(Dataset):
|
||||
[2] https://github.com/abisee/cnn-dailymail/
|
||||
"""
|
||||
|
||||
def __init__(self, tokenizer, prefix="train", data_dir=""):
|
||||
def __init__(self, data_dir="", prefix="train"):
|
||||
assert os.path.isdir(data_dir)
|
||||
self.tokenizer = tokenizer
|
||||
|
||||
# We initialize the class by listing all the files that contain
|
||||
# stories and summaries. Files are not read in memory given
|
||||
@@ -104,31 +103,30 @@ def _add_missing_period(line):
|
||||
# --------------------------
|
||||
|
||||
|
||||
def fit_to_block_size(sequence, block_size, pad_token):
|
||||
def fit_to_block_size(sequence, block_size, pad_token_id):
|
||||
""" Adapt the source and target sequences' lengths to the block size.
|
||||
If the sequence is shorter than the block size we pad it with -1 ids
|
||||
which correspond to padding tokens.
|
||||
If the sequence is shorter we append padding token to the right of the sequence.
|
||||
"""
|
||||
if len(sequence) > block_size:
|
||||
return sequence[:block_size]
|
||||
else:
|
||||
sequence.extend([pad_token] * (block_size - len(sequence)))
|
||||
sequence.extend([pad_token_id] * (block_size - len(sequence)))
|
||||
return sequence
|
||||
|
||||
|
||||
def build_lm_labels(sequence, pad_token):
|
||||
""" Padding token, encoded as 0, are represented by the value -1 so they
|
||||
def build_lm_labels(sequence, pad_token_id):
|
||||
""" Padding token are replaced by the value -1 so they
|
||||
are not taken into account in the loss computation. """
|
||||
padded = sequence.clone()
|
||||
padded[padded == pad_token] = -1
|
||||
padded[padded == pad_token_id] = -1
|
||||
return padded
|
||||
|
||||
|
||||
def build_mask(sequence, pad_token):
|
||||
def build_mask(sequence, pad_token_id):
|
||||
""" Builds the mask. The attention mechanism will only attend to positions
|
||||
with value 1. """
|
||||
mask = torch.ones_like(sequence)
|
||||
idx_pad_tokens = sequence == pad_token
|
||||
idx_pad_tokens = sequence == pad_token_id
|
||||
mask[idx_pad_tokens] = 0
|
||||
return mask
|
||||
|
||||
|
||||
Reference in New Issue
Block a user