Why am I getting KeyError: 'loss'?

Why when I run trainer.train() it gives me Keyerror:‘loss’ previously i use something like start_text and stop_text and I read in previous solution that this the cause of error so I delete it, but it still give same error.Did you have any solution? Thanks

from transformers import AutoTokenizer, AutoModelWithLMHead
tokenizer = AutoTokenizer.from_pretrained("distilgpt2")
model = AutoModelWithLMHead.from_pretrained("distilgpt2")

from datasets import Dataset
dataset = Dataset.from_text('/content/drive/MyDrive/Colab_Notebooks/qna.txt')

tokenizer.pad_token = tokenizer.eos_token
def tokenize_function(examples):
    return tokenizer(examples["text"], padding="max_length", truncation=True)

tokenized_datasets = dataset.map(tokenize_function, batched=True)

from transformers import Trainer, TrainingArguments

training_args = TrainingArguments(
    output_dir='/content/drive/MyDrive/Colab_Notebooks/GPT_checkpoint',          # output directory
    num_train_epochs=3,              # total number of training epochs
    per_device_train_batch_size=1,  # batch size per device during training
    warmup_steps=500,                # number of warmup steps for learning rate scheduler
    weight_decay=0.01,               # strength of weight decay
    logging_dir='/content/drive/MyDrive/Colab_Notebooks/GPT_checkpoint/logs',            # directory for storing logs
trainer = Trainer(
    model=model,                         # the instantiated 🤗 Transformers model to be trained
    args=training_args,                  # training arguments, defined above

Here is the dataset sample:

Was Volta an Italian physicist?
Was Volta an Italian physicist?
Is Volta buried in the city of Pittsburgh?
Is Volta buried in the city of Pittsburgh?

Here is the full error message:

KeyError                                  Traceback (most recent call last)
<ipython-input-17-3435b262f1ae> in <module>()
----> 1 trainer.train()

3 frames
/usr/local/lib/python3.7/dist-packages/transformers/file_utils.py in __getitem__(self, k)
   1804         if isinstance(k, str):
   1805             inner_dict = {k: v for (k, v) in self.items()}
-> 1806             return inner_dict[k]
   1807         else:
   1808             return self.to_tuple()[k]

KeyError: 'loss'
1 Like

There are no labels in your dataset, so it can’t train (and the model does not produce a loss, hence your error). Maybe you wanted to use the DataCollatorForMaskedLM to generate those labels automatically?

1 Like

my dataset has the labels, but also get a KeyError: ‘loss’

>>> d = next(iter(train_loader))
>>> d.keys()
dict_keys(['input_ids', 'attention_mask', 'labels'])
now exiting InteractiveConsole...
[INFO|trainer.py:1202] 2021-12-03 18:24:14,156 >> ***** Running training *****
[INFO|trainer.py:1203] 2021-12-03 18:24:14,156 >>   Num examples = 6667
[INFO|trainer.py:1204] 2021-12-03 18:24:14,156 >>   Num Epochs = 3
[INFO|trainer.py:1205] 2021-12-03 18:24:14,156 >>   Instantaneous batch size per device = 1
[INFO|trainer.py:1206] 2021-12-03 18:24:14,157 >>   Total train batch size (w. parallel, distributed & accumulation) = 1
[INFO|trainer.py:1207] 2021-12-03 18:24:14,157 >>   Gradient Accumulation steps = 1
[INFO|trainer.py:1208] 2021-12-03 18:24:14,157 >>   Total optimization steps = 20001
  0%|                                                                                                                                                         | 0/20001 [00:00<?, ?it/s]Traceback (most recent call last):
  File "run_train.py", line 90, in <module>
  File "run_train.py", line 85, in main
  File "/usr/local/anaconda3/lib/python3.7/site-packages/transformers/trainer.py", line 1323, in train
    tr_loss_step = self.training_step(model, inputs)
  File "/usr/local/anaconda3/lib/python3.7/site-packages/transformers/trainer.py", line 1861, in training_step
    loss = self.compute_loss(model, inputs)
  File "/usr/local/anaconda3/lib/python3.7/site-packages/transformers/trainer.py", line 1905, in compute_loss
    loss = outputs["loss"] if isinstance(outputs, dict) else outputs[0]
  File "/usr/local/anaconda3/lib/python3.7/site-packages/transformers/file_utils.py", line 2125, in __getitem__
    return inner_dict[k]
KeyError: 'loss'

@sgugger is there any advice?

1 Like

You should debug the training step by step as highlighted in this course chapter.

Hi, I met the same situation.I found that Trainer.label_smoother is None,so the Trainer class didn’t calculate the loss,I don’t know how to deal with this.

Hey @sgugger and thank you for the great transformers. I have the same error while I want to fine-tune the facebook/bart-large-cnn for a summarization task. my dataset (after tokenization) looks like this :
train: Dataset({
features: [‘attention_mask’, ‘input_ids’, ‘summary’, ‘text’],
num_rows: 10980
test: Dataset({
features: [‘attention_mask’, ‘input_ids’, ‘summary’, ‘text’],
num_rows: 1161

and I am using thsi line to get the model:
model = AutoModelForSeq2SeqLM.from_pretrained(“facebook/bart-base”)
and training arguments like :
training_args = TrainingArguments(“test_trainer”)

I am also getting this message while trainer.train()
The following columns in the training set don’t have a corresponding argument in BartForConditionalGeneration.forward and have been ignored: text, summary.

can you please guide me?

I would suggest to use 0,1 instead of yes/no! maybe it helps

this video helped me to find a solution for my problem

Thank you Huggingface