IndexError: Target 4 is out of bounds

Hi, I am getting error while training model for token classification

from torch.utils.data import DataLoader
from transformers import DistilBertForTokenClassification, AdamW

device = torch.device(‘cuda’) if torch.cuda.is_available() else torch.device(‘cpu’)

model = DistilBertForTokenClassification.from_pretrained(‘distilbert-base-uncased’)
model.to(device)
model.train()

train_loader = DataLoader(train_dataset, batch_size=16, shuffle=True)

optim = AdamW(model.parameters(), lr=5e-5)

for epoch in range(3):
for batch in train_loader:
optim.zero_grad()
input_ids = batch[‘input_ids’].to(device)
attention_mask = batch[‘attention_mask’].to(device)
labels = batch[‘labels’].to(device)
outputs = model(input_ids, attention_mask=attention_mask, labels=labels)
loss = outputs[0]
loss.backward()
optim.step()

model.eval()

Error:

IndexError Traceback (most recent call last)
in
18 attention_mask = batch[‘attention_mask’].to(device)
19 labels = batch[‘labels’].to(device)
—> 20 outputs = model(input_ids, attention_mask=attention_mask, labels=labels)
21 loss = outputs[0]
22 loss.backward()

~\Anaconda3\lib\site-packages\torch\nn\modules\module.py in _call_impl(self, *input, **kwargs)
1049 if not (self._backward_hooks or self._forward_hooks or self._forward_pre_hooks or _global_backward_hooks
1050 or _global_forward_hooks or _global_forward_pre_hooks):
→ 1051 return forward_call(*input, **kwargs)
1052 # Do not call functions when jit is used
1053 full_backward_hooks, non_full_backward_hooks = [], []

~\Anaconda3\lib\site-packages\transformers\models\distilbert\modeling_distilbert.py in forward(self, input_ids, attention_mask, head_mask, inputs_embeds, labels, output_attentions, output_hidden_states, return_dict)
838 active_loss, labels.view(-1), torch.tensor(loss_fct.ignore_index).type_as(labels)
839 )
→ 840 loss = loss_fct(active_logits, active_labels)
841 else:
842 loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1))

~\Anaconda3\lib\site-packages\torch\nn\modules\module.py in _call_impl(self, *input, **kwargs)
1049 if not (self._backward_hooks or self._forward_hooks or self._forward_pre_hooks or _global_backward_hooks
1050 or _global_forward_hooks or _global_forward_pre_hooks):
→ 1051 return forward_call(*input, **kwargs)
1052 # Do not call functions when jit is used
1053 full_backward_hooks, non_full_backward_hooks = [], []

~\Anaconda3\lib\site-packages\torch\nn\modules\loss.py in forward(self, input, target)
1118
1119 def forward(self, input: Tensor, target: Tensor) → Tensor:
→ 1120 return F.cross_entropy(input, target, weight=self.weight,
1121 ignore_index=self.ignore_index, reduction=self.reduction)
1122

~\Anaconda3\lib\site-packages\torch\nn\functional.py in cross_entropy(input, target, weight, size_average, ignore_index, reduce, reduction)
2822 if size_average is not None or reduce is not None:
2823 reduction = _Reduction.legacy_get_string(size_average, reduce)
→ 2824 return torch._C._nn.cross_entropy_loss(input, target, weight, _Reduction.get_enum(reduction), ignore_index)
2825
2826

IndexError: Target 4 is out of bounds.