首页 > 解决方案 > 一周前代码运行良好,但从昨天开始一直出错:通过 Colab 上的 PyTorch 微调 Bert 模型训练

问题描述

我是伯特的新手。两周前,我成功地在 nlp 分类任务上运行了一个微调的 Bert 模型,尽管结果并不出色。然而,昨天,当我尝试运行相同的代码和数据时,总是出现 AttributeError,它说:“str”对象没有属性“dim”。请知道一切都在 Colab 和 PyTorch Transformers 上。我应该怎么做才能修复它?

这是我在安装变压器时尝试过的一件事,但结果它不起作用:我尝试使用以前的变压器版本而不是 !pip install tr​​ansformers : !pip install --target lib --upgrade transformers==3.5.0

任何反馈将不胜感激!

请参阅以下代码和错误消息:

代码:

  1. 火车定义
# function to train the model
def train():
  
  model.train()

  total_loss, total_accuracy = 0, 0
  
  # empty list to save model predictions
  total_preds=[]
  
  # iterate over batches
  for step,batch in enumerate(train_dataloader):
    
    # progress update after every 50 batches.
    if step % 200 == 0 and not step == 0:
      print('  Batch {:>5,}  of  {:>5,}.'.format(step, len(train_dataloader)))

    # push the batch to gpu
    batch = [r.to(device) for r in batch]
 
    sent_id, mask, labels = batch

    # clear previously calculated gradients 
    model.zero_grad()        

    # get model predictions for the current batch
    preds = model(sent_id, mask)

    # compute the loss between actual and predicted values
    loss = cross_entropy(preds, labels)

    # add on to the total loss
    total_loss = total_loss + loss.item()

    # backward pass to calculate the gradients
    loss.backward()

    # clip the the gradients to 1.0. It helps in preventing the exploding gradient problem
    torch.nn.utils.clip_grad_norm_(model.parameters(), 1.0)

    # update parameters
    optimizer.step()

    # update learning rate schedule
    # scheduler.step()  

    # model predictions are stored on GPU. So, push it to CPU
    preds=preds.detach().cpu().numpy()

    # append the model predictions
    total_preds.append(preds)

  # compute the training loss of the epoch
  avg_loss = total_loss / len(train_dataloader)
  
  # predictions are in the form of (no. of batches, size of batch, no. of classes).
  # reshape the predictions in form of (number of samples, no. of classes)
  total_preds  = np.concatenate(total_preds, axis=0)

  #returns the loss and predictions
  return avg_loss, total_preds
  1. 培训过程
# set initial loss to infinite
best_valid_loss = float('inf')

# empty lists to store training and validation loss of each epoch
train_losses=[]
valid_losses=[]

#for each epoch
for epoch in range(epochs):
     
    print('\n Epoch {:} / {:}'.format(epoch + 1, epochs))
    
    #train model
    train_loss, _ = train()
    
    #evaluate model
    valid_loss, _ = evaluate()
    
    #save the best model
    if valid_loss < best_valid_loss:
        best_valid_loss = valid_loss
        torch.save(model.state_dict(), 'saved_weights.pt')
    
    # append training and validation loss
    train_losses.append(train_loss)
    valid_losses.append(valid_loss)
    
    print(f'\nTraining Loss: {train_loss:.3f}')
    print(f'Validation Loss: {valid_loss:.3f}')
  1. 错误信息:
 Epoch 1 / 10
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-41-c5138ddf6b25> in <module>()
     12 
     13     #train model
---> 14     train_loss, _ = train()
     15 
     16     #evaluate model

5 frames
/usr/local/lib/python3.6/dist-packages/torch/nn/functional.py in linear(input, weight, bias)
   1686         if any([type(t) is not Tensor for t in tens_ops]) and has_torch_function(tens_ops):
   1687             return handle_torch_function(linear, tens_ops, input, weight, bias=bias)
-> 1688     if input.dim() == 2 and bias is not None:
   1689         # fused op is marginally faster
   1690         ret = torch.addmm(bias, input, weight.t())

AttributeError: 'str' object has no attribute 'dim'

标签: tensorflowpytorchbert-language-modelgoogle-colaboratory

解决方案


据我记得 - colab 中有一个旧的变压器版本。2.11.0 之类的东西。尝试:

!pip install transformers~=2.11.0

更改版本号,直到它工作。


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