File size: 7,683 Bytes
3e0cc3d
 
 
 
 
 
 
 
 
 
 
 
 
84a67cd
 
3e0cc3d
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
"""BERT NER Inference."""

from __future__ import absolute_import, division, print_function

import json
import os

import torch
import torch.nn.functional as F
from torch.nn import CrossEntropyLoss
from torch.utils.data import DataLoader, RandomSampler, SequentialSampler, TensorDataset
from torch.utils.data.distributed import DistributedSampler
from tqdm import tqdm, trange
import nltk
nltk.download('punkt')
from nltk import word_tokenize
# from transformers import (BertConfig, BertForTokenClassification,
                                #   BertTokenizer)
from pytorch_transformers import (BertForTokenClassification, BertTokenizer)


class BertNer(BertForTokenClassification):

    def forward(self, input_ids, token_type_ids=None, attention_mask=None, valid_ids=None):
        sequence_output = self.bert(input_ids, token_type_ids, attention_mask, head_mask=None)[0]
        batch_size,max_len,feat_dim = sequence_output.shape
        valid_output = torch.zeros(batch_size,max_len,feat_dim,dtype=torch.float32,device='cpu')
        # valid_output = torch.zeros(batch_size,max_len,feat_dim,dtype=torch.float32,device='cuda' if torch.cuda.is_available() else 'cpu')
        for i in range(batch_size):
            jj = -1
            for j in range(max_len):
                    if valid_ids[i][j].item() == 1:
                        jj += 1
                        valid_output[i][jj] = sequence_output[i][j]
        sequence_output = self.dropout(valid_output)
        logits = self.classifier(sequence_output)
        return logits

class Ner:

    def __init__(self,model_dir: str):
        self.model , self.tokenizer, self.model_config = self.load_model(model_dir)
        self.label_map = self.model_config["label_map"]
        self.max_seq_length = self.model_config["max_seq_length"]
        self.label_map = {int(k):v for k,v in self.label_map.items()}
        self.device = "cpu"
        # self.device = "cuda" if torch.cuda.is_available() else "cpu"
        self.model = self.model.to(self.device)
        self.model.eval()

    def load_model(self, model_dir: str, model_config: str = "model_config.json"):
        model_config = os.path.join(model_dir,model_config)
        model_config = json.load(open(model_config))
        model = BertNer.from_pretrained(model_dir)
        tokenizer = BertTokenizer.from_pretrained(model_dir, do_lower_case=model_config["do_lower"])
        return model, tokenizer, model_config

    def tokenize(self, text: str):
        """ tokenize input"""
        words = word_tokenize(text)
        tokens = []
        valid_positions = []
        for i,word in enumerate(words):
            token = self.tokenizer.tokenize(word)
            tokens.extend(token)
            for i in range(len(token)):
                if i == 0:
                    valid_positions.append(1)
                else:
                    valid_positions.append(0)
        # print("valid positions from text o/p:=>", valid_positions)
        return tokens, valid_positions

    def preprocess(self, text: str):
        """ preprocess """
        tokens, valid_positions = self.tokenize(text)
        ## insert "[CLS]"
        tokens.insert(0,"[CLS]")
        valid_positions.insert(0,1)
        ## insert "[SEP]"
        tokens.append("[SEP]")
        valid_positions.append(1)
        segment_ids = []
        for i in range(len(tokens)):
            segment_ids.append(0)
        input_ids = self.tokenizer.convert_tokens_to_ids(tokens)
        # print("input ids with berttokenizer:=>", input_ids)
        input_mask = [1] * len(input_ids)
        while len(input_ids) < self.max_seq_length:
            input_ids.append(0)
            input_mask.append(0)
            segment_ids.append(0)
            valid_positions.append(0)
        return input_ids,input_mask,segment_ids,valid_positions

    def predict_entity(self, B_lab, I_lab, words, labels, entity_list):
        temp=[]
        entity=[]

        for word, (label, confidence), B_l, I_l in zip(words, labels, B_lab, I_lab):

            if ((label==B_l) or (label==I_l)) and label!='O':
                if label==B_l:
                    entity.append(temp)
                    temp=[]
                    temp.append(label)
                    
                temp.append(word)

        entity.append(temp)
        # print(entity)

        entity_name_label = []
        for entity_name in entity[1:]:
            for ent_key, ent_value in entity_list.items():
                if (ent_key==entity_name[0]):
                    # entity_name_label.append(' '.join(entity_name[1:]) + ": " + ent_value)
                    entity_name_label.append([' '.join(entity_name[1:]), ent_value])
        
        return entity_name_label

    def predict(self, text: str):
        input_ids,input_mask,segment_ids,valid_ids = self.preprocess(text)
        # print("valid ids:=>", segment_ids)
        input_ids = torch.tensor([input_ids],dtype=torch.long,device=self.device)
        input_mask = torch.tensor([input_mask],dtype=torch.long,device=self.device)
        segment_ids = torch.tensor([segment_ids],dtype=torch.long,device=self.device)
        valid_ids = torch.tensor([valid_ids],dtype=torch.long,device=self.device)

        with torch.no_grad():
            logits = self.model(input_ids, segment_ids, input_mask,valid_ids)
        # print("logit values:=>", logits)
        logits = F.softmax(logits,dim=2)
        # print("logit values:=>", logits[0])
        logits_label = torch.argmax(logits,dim=2)
        logits_label = logits_label.detach().cpu().numpy().tolist()[0]
        # print("logits label value list:=>", logits_label)

        logits_confidence = [values[label].item() for values,label in zip(logits[0],logits_label)]

        logits = []
        pos = 0
        for index,mask in enumerate(valid_ids[0]):
            if index == 0:
                continue
            if mask == 1:
                logits.append((logits_label[index-pos],logits_confidence[index-pos]))
            else:
                pos += 1
        logits.pop()
        labels = [(self.label_map[label],confidence) for label,confidence in logits]
        words = word_tokenize(text)

        entity_list = {'B-PER':'Person',
                    'B-FAC':'Facility',
                    'B-LOC':'Location',
                    'B-ORG':'Organization',
                    'B-ART':'Work Of Art',
                    'B-EVENT':'Event',
                    'B-DATE':'Date-Time Entity',
                    'B-TIME':'Date-Time Entity',
                    'B-LAW':'Law Terms',
                    'B-PRODUCT':'Product',
                    'B-PERCENT':'Percentage',
                    'B-MONEY':'Currency',
                    'B-LANGUAGE':'Langauge',
                    'B-NORP':'Nationality / Religion / Political group',
                    'B-QUANTITY':'Quantity',
                    'B-ORDINAL':'Ordinal Number',
                    'B-CARDINAL':'Cardinal Number'}
        
        B_labels=[]
        I_labels=[]
        for label, confidence in labels:
            if (label[:1]=='B'):
                B_labels.append(label)
                I_labels.append('O')
            elif (label[:1]=='I'):
                I_labels.append(label)
                B_labels.append('O')
            else:
                B_labels.append('O')
                I_labels.append('O')

        assert len(labels) == len(words) == len(I_labels) == len(B_labels)

        output = self.predict_entity(B_labels, I_labels, words, labels, entity_list)
        print(output)

        # output = [{"word":word,"tag":label,"confidence":confidence} for word,(label,confidence) in zip(words,labels)]
        return output