Files

81 lines
2.9 KiB
Python

from typing import Tuple, Callable, Optional
import re
from html import unescape
import torch
from torch.utils.data import Dataset
from datasets import load_dataset # Hugging Face (not PyTorch)
from .utils import drop_html_tags
class HfDatasetWithTokenEncode(Dataset):
"""
Hugging Face Dataset wrapper with custom token encode function.
pragma: skip_doc
"""
def __init__(self,
dataset_name: str,
split: str,
sample_field_name: str = "text",
label_field_name: str = "label",
encode: Optional[Callable]=None,
remove_html_tags:Optional[bool]=False,
encode_return_dict:Optional[bool]=False) -> None:
"""
Initializes the dataset by loading Hugging Face dataset.
Args:
dataset_name (str): The name of the Hugging Face dataset.
split (str): The dataset split (e.g., 'train').
sample_field_name (str): Field name for text samples.
label_field_name (str): Field name for labels.
encode (Optional[Callable]): Token encode function
remove_html_tags (Optional[bool]): Remove html tags in text if True.
encode_return_dict (Optional[bool]): Encode function returns a Dict instead of a Tuple.
"""
self.dataset = load_dataset(dataset_name, split=split)
self.sample_field_name = sample_field_name
self.label_field_name = label_field_name
self.encode = encode
self.remove_html_tags = remove_html_tags
self.encode_return_dict = encode_return_dict
def __getitem__(self, idx: int) -> Tuple[torch.Tensor, torch.Tensor]:
"""
Retrieves the (tokens, label) pair at the given index.
Args:
idx (int): Index of the item.
Returns:
Tuple[Tuple[torch.Tensor, torch.Tensor], torch.Tensor]: Tuple of the following:
- Tokens tensor and masks tensor.
- Label tensor
"""
# Get a text sample from database and convert to a word embedding
sample = self.dataset[idx]
if self.remove_html_tags:
text = drop_html_tags(sample[self.sample_field_name])
else:
text = sample[self.sample_field_name]
if self.encode_return_dict:
output = self.encode(text)
tokens = output["input_ids"]
masks = output["attention_mask"]
else:
tokens, masks = self.encode(text)
# Get a corresponding label
label = torch.tensor(sample[self.label_field_name], dtype=torch.long)
return (tokens.squeeze(0), masks.squeeze(0)), label.squeeze(0)
def __len__(self) -> int:
"""
Returns the number of samples in the dataset.
Returns:
int: Dataset length.
"""
return len(self.dataset)