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from typing import Optional, List, Tuple, Any | |
from collections import OrderedDict | |
from transformers import logging, RobertaForTokenClassification | |
from torch.nn.utils.rnn import pack_padded_sequence, pad_packed_sequence | |
from torchcrf import CRF | |
import torch | |
import torch.nn as nn | |
import torch.nn.functional as F | |
logging.set_verbosity_error() | |
import torch | |
logging.set_verbosity_error() | |
class NerOutput(OrderedDict): | |
loss: Optional[torch.FloatTensor] = torch.FloatTensor([0.0]) | |
tags: Optional[List[int]] = [] | |
def __getitem__(self, k): | |
if isinstance(k, str): | |
inner_dict = {k: v for (k, v) in self.items()} | |
return inner_dict[k] | |
else: | |
return self.to_tuple()[k] | |
def __setattr__(self, name, value): | |
if name in self.keys() and value is not None: | |
super().__setitem__(name, value) | |
super().__setattr__(name, value) | |
def __setitem__(self, key, value): | |
super().__setitem__(key, value) | |
super().__setattr__(key, value) | |
def to_tuple(self) -> Tuple[Any]: | |
return tuple(self[k] for k in self.keys()) | |
class PhoBertSoftmax(RobertaForTokenClassification): | |
def __init__(self, config, **kwargs): | |
super(PhoBertSoftmax, self).__init__(config=config, **kwargs) | |
self.num_labels = config.num_labels | |
def forward(self, input_ids, token_type_ids=None, attention_mask=None, labels=None, valid_ids=None, | |
label_masks=None): | |
seq_output = self.roberta(input_ids=input_ids, | |
token_type_ids=token_type_ids, | |
attention_mask=attention_mask, | |
head_mask=None)[0] | |
seq_output = self.dropout(seq_output) | |
logits = self.classifier(seq_output) | |
probs = F.log_softmax(logits, dim=2) | |
label_masks = label_masks.view(-1) != 0 | |
seq_tags = torch.masked_select(torch.argmax(probs, dim=2).view(-1), label_masks).tolist() | |
if labels is not None: | |
loss_func = nn.CrossEntropyLoss() | |
loss = loss_func(logits.view(-1, self.num_labels), labels.view(-1)) | |
return NerOutput(loss=loss, tags=seq_tags) | |
else: | |
return NerOutput(tags=seq_tags) | |
class PhoBertCrf(RobertaForTokenClassification): | |
def __init__(self, config): | |
super(PhoBertCrf, self).__init__(config=config) | |
self.num_labels = config.num_labels | |
self.crf = CRF(config.num_labels, batch_first=True) | |
self.init_weights() | |
def forward(self, input_ids, token_type_ids=None, attention_mask=None, labels=None, valid_ids=None, | |
label_masks=None): | |
seq_outputs = self.roberta(input_ids=input_ids, | |
token_type_ids=token_type_ids, | |
attention_mask=attention_mask, | |
head_mask=None)[0] | |
batch_size, max_len, feat_dim = seq_outputs.shape | |
range_vector = torch.arange(0, batch_size, dtype=torch.long, device=seq_outputs.device).unsqueeze(1) | |
seq_outputs = seq_outputs[range_vector, valid_ids] | |
seq_outputs = self.dropout(seq_outputs) | |
logits = self.classifier(seq_outputs) | |
seq_tags = self.crf.decode(logits, mask=label_masks != 0) | |
if labels is not None: | |
log_likelihood = self.crf(logits, labels, mask=label_masks.type(torch.uint8)) | |
return NerOutput(loss=-1.0 * log_likelihood, tags=seq_tags) | |
else: | |
return NerOutput(tags=seq_tags) | |
class PhoBertLstmCrf(RobertaForTokenClassification): | |
def __init__(self, config): | |
super(PhoBertLstmCrf, self).__init__(config=config) | |
self.num_labels = config.num_labels | |
self.lstm = nn.LSTM(input_size=config.hidden_size, | |
hidden_size=config.hidden_size // 2, | |
num_layers=1, | |
batch_first=True, | |
bidirectional=True) | |
self.crf = CRF(config.num_labels, batch_first=True) | |
def sort_batch(src_tensor, lengths): | |
""" | |
Sort a minibatch by the length of the sequences with the longest sequences first | |
return the sorted batch targes and sequence lengths. | |
This way the output can be used by pack_padded_sequences(...) | |
""" | |
seq_lengths, perm_idx = lengths.sort(0, descending=True) | |
seq_tensor = src_tensor[perm_idx] | |
_, reversed_idx = perm_idx.sort(0, descending=False) | |
return seq_tensor, seq_lengths, reversed_idx | |
def forward(self, input_ids, token_type_ids=None, attention_mask=None, labels=None, valid_ids=None, | |
label_masks=None): | |
seq_outputs = self.roberta(input_ids=input_ids, | |
token_type_ids=token_type_ids, | |
attention_mask=attention_mask, | |
head_mask=None)[0] | |
batch_size, max_len, feat_dim = seq_outputs.shape | |
seq_lens = torch.sum(label_masks, dim=-1) | |
range_vector = torch.arange(0, batch_size, dtype=torch.long, device=seq_outputs.device).unsqueeze(1) | |
seq_outputs = seq_outputs[range_vector, valid_ids] | |
sorted_seq_outputs, sorted_seq_lens, reversed_idx = self.sort_batch(src_tensor=seq_outputs, | |
lengths=seq_lens) | |
packed_words = pack_padded_sequence(sorted_seq_outputs, sorted_seq_lens.cpu(), True) | |
lstm_outs, _ = self.lstm(packed_words) | |
lstm_outs, _ = pad_packed_sequence(lstm_outs, batch_first=True, total_length=max_len) | |
seq_outputs = lstm_outs[reversed_idx] | |
seq_outputs = self.dropout(seq_outputs) | |
logits = self.classifier(seq_outputs) | |
seq_tags = self.crf.decode(logits, mask=label_masks != 0) | |
if labels is not None: | |
log_likelihood = self.crf(logits, labels, mask=label_masks.type(torch.uint8)) | |
return NerOutput(loss=-1.0 * log_likelihood, tags=seq_tags) | |
else: | |
return NerOutput(tags=seq_tags) |