Create model.py
Browse files
model.py
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from transformers import PretrainedConfigfrom abc import ABCMeta
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import torch
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from transformers.pytorch_utils import nn
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from transformers import BertModel, BertConfig
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import torch
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import torch.nn.functional as F
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from transformers import PreTrainedModel
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from transformers.modeling_outputs import SequenceClassifierOutput
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from transformers import PretrainedConfig
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class BertLSTMConfig(PretrainedConfig):
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model_type = "bertLSTMForSequenceClassification"
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def __init__(self,
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num_classes=2,
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embed_dim=768,
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num_layers=12,
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hidden_dim_lstm=256, # New parameter for LSTM
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dropout_rate=0.1,
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**kwargs):
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super().__init__(**kwargs)
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self.num_classes = num_classes
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self.embed_dim = embed_dim
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self.num_layers = num_layers
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self.hidden_dim_lstm = hidden_dim_lstm # Assign LSTM hidden dimension
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self.dropout_rate = dropout_rate
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self.id2label = {
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0: "fake",
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1: "true",
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}
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self.label2id = {
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"fake": 0,
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"true": 1,
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}
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class BertLSTMForSequenceClassification(PreTrainedModel, metaclass=ABCMeta):
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config_class = BertLSTMConfig
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def __init__(self, config):
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super(BertLSTMForSequenceClassification, self).__init__(config)
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self.num_classes = config.num_classes
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self.embed_dim = config.embed_dim
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self.num_layers = config.num_layers
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self.hidden_dim_lstm = config.hidden_dim_lstm
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self.dropout = nn.Dropout(config.dropout_rate)
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self.bert = BertModel.from_pretrained('bert-base-uncased')
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print("BERT Model Loaded")
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self.lstm = nn.LSTM(self.embed_dim, self.hidden_dim_lstm, batch_first=True, num_layers=3)
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self.fc = nn.Linear(self.hidden_dim_lstm, self.num_classes)
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def forward(self, input_ids, attention_mask, token_type_ids, labels=None):
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bert_output = self.bert(input_ids=input_ids, attention_mask=attention_mask, token_type_ids=token_type_ids)
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pooled_output = bert_output.pooler_output # Use the pooled output for classification
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out, _ = self.lstm(pooled_output.unsqueeze(1))
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out = self.dropout(out[:, -1, :])
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logits = self.fc(out)
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loss = None
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if labels is not None:
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loss = F.cross_entropy(logits, labels)
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out = SequenceClassifierOutput(
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loss=loss,
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logits=logits,
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hidden_states=bert_output.hidden_states,
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attentions=bert_output.attentions,
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)
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return out
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