Files
2020-08-28 14:27:42 -07:00

175 lines
6.0 KiB
Python

import linecache
import re
import string
from collections import Counter
from logging import getLogger
from pathlib import Path
from typing import Dict, List
import torch
from torch.utils.data import Dataset
from examples.seq2seq.utils import SortishSampler, trim_batch
from transformers import BartTokenizer, T5Tokenizer
def encode_line(tokenizer, line, max_length, padding_side, pad_to_max_length=True, return_tensors="pt"):
extra_kw = {"add_prefix_space": True} if isinstance(tokenizer, BartTokenizer) else {}
tokenizer.padding_side = padding_side
return tokenizer(
[line],
max_length=max_length,
padding="max_length" if pad_to_max_length else None,
truncation=True,
return_tensors=return_tensors,
add_special_tokens=True,
**extra_kw,
)
class Seq2SeqDataset(Dataset):
def __init__(
self,
tokenizer,
data_dir,
max_source_length,
max_target_length,
type_path="train",
n_obs=None,
src_lang=None,
tgt_lang=None,
prefix="",
):
super().__init__()
self.src_file = Path(data_dir).joinpath(type_path + ".source")
self.tgt_file = Path(data_dir).joinpath(type_path + ".target")
self.src_lens = self.get_char_lens(self.src_file)
self.max_source_length = max_source_length
self.max_target_length = max_target_length
assert min(self.src_lens) > 0, f"found empty line in {self.src_file}"
self.tokenizer = tokenizer
self.prefix = prefix
if n_obs is not None:
self.src_lens = self.src_lens[:n_obs]
self.pad_token_id = self.tokenizer.pad_token_id
self.src_lang = src_lang
self.tgt_lang = tgt_lang
def __len__(self):
return len(self.src_lens)
def __getitem__(self, index) -> Dict[str, torch.Tensor]:
index = index + 1 # linecache starts at 1
source_line = self.prefix + linecache.getline(str(self.src_file), index).rstrip("\n")
tgt_line = linecache.getline(str(self.tgt_file), index).rstrip("\n")
assert source_line, f"empty source line for index {index}"
assert tgt_line, f"empty tgt line for index {index}"
# Need to add eos token manually for T5
if isinstance(self.tokenizer, T5Tokenizer):
source_line += self.tokenizer.eos_token
tgt_line += self.tokenizer.eos_token
# Pad source to the left and target to the right
source_inputs = encode_line(self.tokenizer, source_line, self.max_source_length, "right") # "left")
target_inputs = encode_line(self.tokenizer, tgt_line, self.max_target_length, "right")
source_ids = source_inputs["input_ids"].squeeze()
target_ids = target_inputs["input_ids"].squeeze()
src_mask = source_inputs["attention_mask"].squeeze()
return {
"input_ids": source_ids,
"attention_mask": src_mask,
"decoder_input_ids": target_ids,
}
@staticmethod
def get_char_lens(data_file):
return [len(x) for x in Path(data_file).open().readlines()]
def collate_fn(self, batch) -> Dict[str, torch.Tensor]:
input_ids = torch.stack([x["input_ids"] for x in batch])
masks = torch.stack([x["attention_mask"] for x in batch])
target_ids = torch.stack([x["decoder_input_ids"] for x in batch])
pad_token_id = self.pad_token_id
y = trim_batch(target_ids, pad_token_id)
source_ids, source_mask = trim_batch(input_ids, pad_token_id, attention_mask=masks)
batch = {
"input_ids": source_ids,
"attention_mask": source_mask,
"decoder_input_ids": y,
}
return batch
def make_sortish_sampler(self, batch_size):
return SortishSampler(self.src_lens, batch_size)
logger = getLogger(__name__)
def normalize_answer(s):
"""Lower text and remove punctuation, articles and extra whitespace."""
def remove_articles(text):
return re.sub(r"\b(a|an|the)\b", " ", text)
def white_space_fix(text):
return " ".join(text.split())
def remove_punc(text):
exclude = set(string.punctuation)
return "".join(ch for ch in text if ch not in exclude)
def lower(text):
return text.lower()
return white_space_fix(remove_articles(remove_punc(lower(s))))
def f1_score(prediction, ground_truth):
prediction_tokens = normalize_answer(prediction).split()
ground_truth_tokens = normalize_answer(ground_truth).split()
common = Counter(prediction_tokens) & Counter(ground_truth_tokens)
num_same = sum(common.values())
if num_same == 0:
return 0
precision = 1.0 * num_same / len(prediction_tokens)
recall = 1.0 * num_same / len(ground_truth_tokens)
f1 = (2 * precision * recall) / (precision + recall)
return f1
def exact_match_score(prediction, ground_truth):
return normalize_answer(prediction) == normalize_answer(ground_truth)
def calculate_exact_match(output_lns: List[str], reference_lns: List[str]) -> Dict:
assert len(output_lns) == len(reference_lns)
em = 0
for hypo, pred in zip(output_lns, reference_lns):
em += exact_match_score(hypo, pred)
if len(output_lns) > 0:
em /= len(output_lns)
return {"em": em}
def is_rag_model(model_prefix):
return model_prefix.startswith("rag")
def set_extra_model_params(extra_params, hparams, config):
equivalent_param = {p: p for p in extra_params}
# T5 models don't have `dropout` param, they have `dropout_rate` instead
equivalent_param["dropout"] = "dropout_rate"
for p in extra_params:
if getattr(hparams, p, None):
if not hasattr(config, p) and not hasattr(config, equivalent_param[p]):
logger.info("config doesn't have a `{}` attribute".format(p))
delattr(hparams, p)
continue
set_p = p if hasattr(config, p) else equivalent_param[p]
setattr(config, set_p, getattr(hparams, p))
delattr(hparams, p)
return hparams, config