mirror of
https://github.com/openai/gpt-2-output-dataset
synced 2025-08-22 18:07:53 +00:00
87 lines
3.5 KiB
Python
87 lines
3.5 KiB
Python
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import json
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import numpy as np
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from typing import List
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import torch
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from torch.utils.data import Dataset
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from tqdm import tqdm
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from transformers import PreTrainedTokenizer
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from .download import download
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def load_texts(data_file, expected_size=None):
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texts = []
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for line in tqdm(open(data_file), total=expected_size, desc=f'Loading {data_file}'):
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texts.append(json.loads(line)['text'])
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return texts
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class Corpus:
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def __init__(self, name, data_dir='data', skip_train=False):
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download(name, data_dir=data_dir)
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self.name = name
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self.train = load_texts(f'{data_dir}/{name}.train.jsonl', expected_size=250000) if not skip_train else None
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self.test = load_texts(f'{data_dir}/{name}.test.jsonl', expected_size=5000)
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self.valid = load_texts(f'{data_dir}/{name}.valid.jsonl', expected_size=5000)
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class EncodedDataset(Dataset):
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def __init__(self, real_texts: List[str], fake_texts: List[str], tokenizer: PreTrainedTokenizer,
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max_sequence_length: int = None, min_sequence_length: int = None, epoch_size: int = None,
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token_dropout: float = None, seed: int = None):
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self.real_texts = real_texts
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self.fake_texts = fake_texts
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self.tokenizer = tokenizer
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self.max_sequence_length = max_sequence_length
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self.min_sequence_length = min_sequence_length
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self.epoch_size = epoch_size
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self.token_dropout = token_dropout
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self.random = np.random.RandomState(seed)
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def __len__(self):
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return self.epoch_size or len(self.real_texts) + len(self.fake_texts)
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def __getitem__(self, index):
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if self.epoch_size is not None:
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label = self.random.randint(2)
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texts = [self.fake_texts, self.real_texts][label]
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text = texts[self.random.randint(len(texts))]
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else:
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if index < len(self.real_texts):
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text = self.real_texts[index]
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label = 1
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else:
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text = self.fake_texts[index - len(self.real_texts)]
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label = 0
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tokens = self.tokenizer.encode(text)
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if self.max_sequence_length is None:
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tokens = tokens[:self.tokenizer.max_len - 2]
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else:
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output_length = min(len(tokens), self.max_sequence_length)
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if self.min_sequence_length:
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output_length = self.random.randint(min(self.min_sequence_length, len(tokens)), output_length + 1)
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start_index = 0 if len(tokens) <= output_length else self.random.randint(0, len(tokens) - output_length + 1)
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end_index = start_index + output_length
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tokens = tokens[start_index:end_index]
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if self.token_dropout:
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dropout_mask = self.random.binomial(1, self.token_dropout, len(tokens)).astype(np.bool)
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tokens = np.array(tokens)
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tokens[dropout_mask] = self.tokenizer.unk_token_id
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tokens = tokens.tolist()
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if self.max_sequence_length is None or len(tokens) == self.max_sequence_length:
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mask = torch.ones(len(tokens) + 2)
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return torch.tensor([self.tokenizer.bos_token_id] + tokens + [self.tokenizer.eos_token_id]), mask, label
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padding = [self.tokenizer.pad_token_id] * (self.max_sequence_length - len(tokens))
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tokens = torch.tensor([self.tokenizer.bos_token_id] + tokens + [self.tokenizer.eos_token_id] + padding)
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mask = torch.ones(tokens.shape[0])
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mask[-len(padding):] = 0
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return tokens, mask, label
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