目录
DataCollatorMixin类
class DataCollatorMixin:
def __call__(self, features, return_tensors=None):
if return_tensors is None:
return_tensors = self.return_tensors
if return_tensors == "pd":
return self.paddle_call(features)
elif return_tensors == "np":
return self.numpy_call(features)
else:
raise ValueError(f"Framework '{return_tensors}' not recognized!")
DataCollatorForTokenClassification类
@dataclass
class DataCollatorForTokenClassification(DataCollatorMixin):
"""
Data collator that will dynamically pad the inputs received, as well as the labels.
Args:
tokenizer ([`PretrainedTokenizer`] or [`PretrainedFasterTokenizer`]):
The tokenizer used for encoding the data.
padding (`bool`, `str` or [`~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
is 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 = "pd"
def paddle_call(self, features):
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="pd" if labels is None else None,
)
if labels is None:
return batch
sequence_length = paddle.to_tensor(batch["input_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]
batch = {
k: paddle.to_tensor(v, dtype='int64')
for k, v in batch.items()
}
return batch
def numpy_call(self, features):
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="np" if labels is None else None,
)
if labels is None:
return batch
sequence_length = np.array(batch["input_ids"]).shape[1]
padding_side = self.tokenizer.padding_side
if padding_side == "right":
batch["labels"] = [
list(label) + [self.label_pad_token_id] *
(sequence_length - len(label)) for label in labels
]
else:
batch["labels"] = [[self.label_pad_token_id] *
(sequence_length - len(label)) + list(label)
for label in labels]
batch = {k: np.array(v, dtype=np.int64) for k, v in batch.items()}
return batch