File size: 10,807 Bytes
b5dbcf3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
import os
import logging
from tqdm import tqdm, trange

import numpy as np
import torch
from torch.utils.data import DataLoader, RandomSampler, SequentialSampler
from transformers import BertConfig, AdamW, get_linear_schedule_with_warmup

from utils import MODEL_CLASSES, compute_metrics, get_intent_labels, get_slot_labels

logger = logging.getLogger(__name__)


class Trainer(object):
    def __init__(self, args, train_dataset=None, dev_dataset=None, test_dataset=None):
        self.args = args
        self.train_dataset = train_dataset
        self.dev_dataset = dev_dataset
        self.test_dataset = test_dataset

        self.intent_label_lst = get_intent_labels(args)
        self.slot_label_lst = get_slot_labels(args)
        # Use cross entropy ignore index as padding label id so that only real label ids contribute to the loss later
        self.pad_token_label_id = args.ignore_index

        self.config_class, self.model_class, _ = MODEL_CLASSES[args.model_type]
        self.config = self.config_class.from_pretrained(args.model_name_or_path, finetuning_task=args.task)
        self.model = self.model_class.from_pretrained(args.model_name_or_path,
                                                      config=self.config,
                                                      args=args,
                                                      intent_label_lst=self.intent_label_lst,
                                                      slot_label_lst=self.slot_label_lst)

        # GPU or CPU
        self.device = "cuda" if torch.cuda.is_available() and not args.no_cuda else "cpu"
        self.model.to(self.device)

    def train(self):
        train_sampler = RandomSampler(self.train_dataset)
        train_dataloader = DataLoader(self.train_dataset, sampler=train_sampler, batch_size=self.args.train_batch_size)

        if self.args.max_steps > 0:
            t_total = self.args.max_steps
            self.args.num_train_epochs = self.args.max_steps // (len(train_dataloader) // self.args.gradient_accumulation_steps) + 1
        else:
            t_total = len(train_dataloader) // self.args.gradient_accumulation_steps * self.args.num_train_epochs

        # Prepare optimizer and schedule (linear warmup and decay)
        no_decay = ['bias', 'LayerNorm.weight']
        optimizer_grouped_parameters = [
            {'params': [p for n, p in self.model.named_parameters() if not any(nd in n for nd in no_decay)],
             'weight_decay': self.args.weight_decay},
            {'params': [p for n, p in self.model.named_parameters() if any(nd in n for nd in no_decay)], 'weight_decay': 0.0}
        ]
        optimizer = AdamW(optimizer_grouped_parameters, lr=self.args.learning_rate, eps=self.args.adam_epsilon)
        scheduler = get_linear_schedule_with_warmup(optimizer, num_warmup_steps=self.args.warmup_steps, num_training_steps=t_total)

        # Train!
        logger.info("***** Running training *****")
        logger.info("  Num examples = %d", len(self.train_dataset))
        logger.info("  Num Epochs = %d", self.args.num_train_epochs)
        logger.info("  Total train batch size = %d", self.args.train_batch_size)
        logger.info("  Gradient Accumulation steps = %d", self.args.gradient_accumulation_steps)
        logger.info("  Total optimization steps = %d", t_total)
        logger.info("  Logging steps = %d", self.args.logging_steps)
        logger.info("  Save steps = %d", self.args.save_steps)

        global_step = 0
        tr_loss = 0.0
        self.model.zero_grad()

        train_iterator = trange(int(self.args.num_train_epochs), desc="Epoch")

        for _ in train_iterator:
            epoch_iterator = tqdm(train_dataloader, desc="Iteration")
            for step, batch in enumerate(epoch_iterator):
                self.model.train()
                batch = tuple(t.to(self.device) for t in batch)  # GPU or CPU

                inputs = {'input_ids': batch[0],
                          'attention_mask': batch[1],
                          'intent_label_ids': batch[3],
                          'slot_labels_ids': batch[4]}
                if self.args.model_type != 'distilbert':
                    inputs['token_type_ids'] = batch[2]
                outputs = self.model(**inputs)
                loss = outputs[0]

                if self.args.gradient_accumulation_steps > 1:
                    loss = loss / self.args.gradient_accumulation_steps

                loss.backward()

                tr_loss += loss.item()
                if (step + 1) % self.args.gradient_accumulation_steps == 0:
                    torch.nn.utils.clip_grad_norm_(self.model.parameters(), self.args.max_grad_norm)

                    optimizer.step()
                    scheduler.step()  # Update learning rate schedule
                    self.model.zero_grad()
                    global_step += 1

                    if self.args.logging_steps > 0 and global_step % self.args.logging_steps == 0:
                        self.evaluate("dev")

                    if self.args.save_steps > 0 and global_step % self.args.save_steps == 0:
                        self.save_model()

                if 0 < self.args.max_steps < global_step:
                    epoch_iterator.close()
                    break

            if 0 < self.args.max_steps < global_step:
                train_iterator.close()
                break

        return global_step, tr_loss / global_step

    def evaluate(self, mode):
        if mode == 'test':
            dataset = self.test_dataset
        elif mode == 'dev':
            dataset = self.dev_dataset
        else:
            raise Exception("Only dev and test dataset available")

        eval_sampler = SequentialSampler(dataset)
        eval_dataloader = DataLoader(dataset, sampler=eval_sampler, batch_size=self.args.eval_batch_size)

        # Eval!
        logger.info("***** Running evaluation on %s dataset *****", mode)
        logger.info("  Num examples = %d", len(dataset))
        logger.info("  Batch size = %d", self.args.eval_batch_size)
        eval_loss = 0.0
        nb_eval_steps = 0
        intent_preds = None
        slot_preds = None
        out_intent_label_ids = None
        out_slot_labels_ids = None

        self.model.eval()

        for batch in tqdm(eval_dataloader, desc="Evaluating"):
            batch = tuple(t.to(self.device) for t in batch)
            with torch.no_grad():
                inputs = {'input_ids': batch[0],
                          'attention_mask': batch[1],
                          'intent_label_ids': batch[3],
                          'slot_labels_ids': batch[4]}
                if self.args.model_type != 'distilbert':
                    inputs['token_type_ids'] = batch[2]
                outputs = self.model(**inputs)
                tmp_eval_loss, (intent_logits, slot_logits) = outputs[:2]

                eval_loss += tmp_eval_loss.mean().item()
            nb_eval_steps += 1

            # Intent prediction
            if intent_preds is None:
                intent_preds = intent_logits.detach().cpu().numpy()
                out_intent_label_ids = inputs['intent_label_ids'].detach().cpu().numpy()
            else:
                intent_preds = np.append(intent_preds, intent_logits.detach().cpu().numpy(), axis=0)
                out_intent_label_ids = np.append(
                    out_intent_label_ids, inputs['intent_label_ids'].detach().cpu().numpy(), axis=0)

            # Slot prediction
            if slot_preds is None:
                if self.args.use_crf:
                    # decode() in `torchcrf` returns list with best index directly
                    slot_preds = np.array(self.model.crf.decode(slot_logits))
                else:
                    slot_preds = slot_logits.detach().cpu().numpy()

                out_slot_labels_ids = inputs["slot_labels_ids"].detach().cpu().numpy()
            else:
                if self.args.use_crf:
                    slot_preds = np.append(slot_preds, np.array(self.model.crf.decode(slot_logits)), axis=0)
                else:
                    slot_preds = np.append(slot_preds, slot_logits.detach().cpu().numpy(), axis=0)

                out_slot_labels_ids = np.append(out_slot_labels_ids, inputs["slot_labels_ids"].detach().cpu().numpy(), axis=0)

        eval_loss = eval_loss / nb_eval_steps
        results = {
            "loss": eval_loss
        }

        # Intent result
        intent_preds = np.argmax(intent_preds, axis=1)

        # Slot result
        if not self.args.use_crf:
            slot_preds = np.argmax(slot_preds, axis=2)
        slot_label_map = {i: label for i, label in enumerate(self.slot_label_lst)}
        out_slot_label_list = [[] for _ in range(out_slot_labels_ids.shape[0])]
        slot_preds_list = [[] for _ in range(out_slot_labels_ids.shape[0])]

        for i in range(out_slot_labels_ids.shape[0]):
            for j in range(out_slot_labels_ids.shape[1]):
                if out_slot_labels_ids[i, j] != self.pad_token_label_id:
                    out_slot_label_list[i].append(slot_label_map[out_slot_labels_ids[i][j]])
                    slot_preds_list[i].append(slot_label_map[slot_preds[i][j]])

        total_result = compute_metrics(intent_preds, out_intent_label_ids, slot_preds_list, out_slot_label_list)
        results.update(total_result)

        logger.info("***** Eval results *****")
        for key in sorted(results.keys()):
            logger.info("  %s = %s", key, str(results[key]))

        return results

    def save_model(self):
        # Save model checkpoint (Overwrite)
        if not os.path.exists(self.args.model_dir):
            os.makedirs(self.args.model_dir)
        model_to_save = self.model.module if hasattr(self.model, 'module') else self.model
        model_to_save.save_pretrained(self.args.model_dir)

        # Save training arguments together with the trained model
        torch.save(self.args, os.path.join(self.args.model_dir, 'training_args.bin'))
        logger.info("Saving model checkpoint to %s", self.args.model_dir)

    def load_model(self):
        # Check whether model exists
        if not os.path.exists(self.args.model_dir):
            raise Exception("Model doesn't exists! Train first!")

        try:
            self.model = self.model_class.from_pretrained(self.args.model_dir,
                                                          args=self.args,
                                                          intent_label_lst=self.intent_label_lst,
                                                          slot_label_lst=self.slot_label_lst)
            self.model.to(self.device)
            logger.info("***** Model Loaded *****")
        except:
            raise Exception("Some model files might be missing...")