File size: 5,106 Bytes
ee6e328
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
import unicodedata
from dataclasses import dataclass
from typing import Optional, Union

import numpy as np

from transformers.data.data_collator import DataCollatorMixin
from transformers.file_utils import PaddingStrategy
from transformers.tokenization_utils_base import PreTrainedTokenizerBase


def padding_tensor(sequences, padding_value, padding_side, sequence_length):
    if isinstance(padding_value, tuple):
        out_tensor = np.full((len(sequences), sequence_length, 2), padding_value)
    else:
        out_tensor = np.full((len(sequences), sequence_length), padding_value)

    for i, tensor in enumerate(sequences):
        if padding_side == "right":
            if isinstance(padding_value, tuple):
                out_tensor[i, : len(tensor[:sequence_length]), :2] = tensor[:sequence_length]
            else:
                out_tensor[i, : len(tensor[:sequence_length])] = tensor[:sequence_length]
        else:
            if isinstance(padding_value, tuple):
                out_tensor[i, len(tensor[:sequence_length]) - 1 :, :2] = tensor[:sequence_length]
            else:
                out_tensor[i, len(tensor[:sequence_length]) - 1 :] = tensor[:sequence_length]

    return out_tensor.tolist()


def is_punctuation(char):
    cp = ord(char)
    if (cp >= 33 and cp <= 47) or (cp >= 58 and cp <= 64) or (cp >= 91 and cp <= 96) or (cp >= 123 and cp <= 126):
        return True
    cat = unicodedata.category(char)
    if cat.startswith("P"):
        return True
    return False


@dataclass
class DataCollatorForLukeTokenClassification(DataCollatorMixin):
    """
    Data collator that will dynamically pad the inputs received, as well as the labels.

    Args:
        tokenizer ([`PreTrainedTokenizer`] or [`PreTrainedTokenizerFast`]):
            The tokenizer used for encoding the data.
        padding (`bool`, `str` or [`~file_utils.PaddingStrategy`], *optional*, defaults to `True`):
            Select a strategy to pad the returned sequences (according to the model's padding side and padding index)
            among:

            - `True` or `'longest'`: Pad to the longest sequence in the batch (or no padding if only a single
              sequence if provided).
            - `'max_length'`: Pad to a maximum length specified with the argument `max_length` or to the
              maximum acceptable input length for the model if that argument is not provided.
            - `False` or `'do_not_pad'` (default): No padding (i.e., can output a batch with sequences of
              different lengths).
        max_length (`int`, *optional*):
            Maximum length of the returned list and optionally padding length (see above).
        pad_to_multiple_of (`int`, *optional*):
            If set will pad the sequence to a multiple of the provided value.

            This is especially useful to enable the use of Tensor Cores on NVIDIA hardware with compute capability >=
            7.5 (Volta).
        label_pad_token_id (`int`, *optional*, defaults to -100):
            The id to use when padding the labels (-100 will be automatically ignore by PyTorch loss functions).
        return_tensors (`str`):
            The type of Tensor to return. Allowable values are "np", "pt" and "tf".
    """

    tokenizer: PreTrainedTokenizerBase
    padding: Union[bool, str, PaddingStrategy] = True
    max_length: Optional[int] = None
    pad_to_multiple_of: Optional[int] = None
    label_pad_token_id: int = -100
    return_tensors: str = "pt"

    def torch_call(self, features):
        import torch

        label_name = "label" if "label" in features[0].keys() else "labels"
        labels = [feature[label_name] for feature in features] if label_name in features[0].keys() else None
        batch = self.tokenizer.pad(
            features,
            padding=self.padding,
            max_length=self.max_length,
            pad_to_multiple_of=self.pad_to_multiple_of,
            # Conversion to tensors will fail if we have labels as they are not of the same length yet.
            return_tensors="pt" if labels is None else None,
        )

        if labels is None:
            return batch

        sequence_length = torch.tensor(batch["entity_ids"]).shape[1]
        padding_side = self.tokenizer.padding_side
        if padding_side == "right":
            batch[label_name] = [
                list(label) + [self.label_pad_token_id] * (sequence_length - len(label)) for label in labels
            ]
        else:
            batch[label_name] = [
                [self.label_pad_token_id] * (sequence_length - len(label)) + list(label) for label in labels
            ]

        ner_tags = [feature["ner_tags"] for feature in features]
        batch["ner_tags"] = padding_tensor(ner_tags, -1, padding_side, sequence_length)
        original_entity_spans = [feature["original_entity_spans"] for feature in features]
        batch["original_entity_spans"] = padding_tensor(original_entity_spans, (-1, -1), padding_side, sequence_length)
        batch = {k: torch.tensor(v, dtype=torch.int64) for k, v in batch.items()}

        return batch