Create chat.py
Browse files
chat.py
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import torch
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from torch import nn
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from transformers import BertTokenizer, BertForSequenceClassification, TrainingArguments
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class CustomTrainer(Trainer):
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def compute_loss(self, model, inputs, return_outputs=False):
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labels = inputs.get("labels")
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outputs = model(**inputs)
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logits = outputs.get("logits")
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loss_fct = nn.CrossEntropyLoss(weight=torch.tensor([1.0, 2.0, 3.0]))
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loss = loss_fct(logits.view(-1, self.model.config.num_labels), labels.view(-1))
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return (loss, outputs) if return_outputs else loss
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# Load pre-trained model
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model = BertForSequenceClassification.from_pretrained("bert-base-uncased")
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# Load tokenizer
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tokenizer = BertTokenizer.from_pretrained("bert-base-uncased")
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# Tokenize your dataset (you would need to define this yourself)
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# This is a placeholder and will not run
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train_encodings = tokenizer(train_texts, truncation=True, padding=True)
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train_labels = torch.tensor(train_labels)
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# Define a PyTorch Dataset from the encodings and the labels
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class MyDataset(torch.utils.data.Dataset):
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def __init__(self, encodings, labels):
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self.encodings = encodings
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self.labels = labels
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def __getitem__(self, idx):
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item = {k: torch.tensor(v[idx]) for k, v in self.encodings.items()}
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item['labels'] = torch.tensor(self.labels[idx])
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return item
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def __len__(self):
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return len(self.labels)
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# Create a Dataset object
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train_dataset = MyDataset(train_encodings, train_labels)
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# Define training arguments
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training_args = TrainingArguments(
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output_dir='./results',
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num_train_epochs=3,
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per_device_train_batch_size=16,
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warmup_steps=500,
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weight_decay=0.01,
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)
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# Initialize the trainer
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trainer = CustomTrainer(
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model=model,
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args=training_args,
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train_dataset=train_dataset,
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)
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# Train the model
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trainer.train()
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