NER example
https://github.com/huggingface/transformers/blob/9e56aff58a742b48fc8edea8d28d5b80330efbcc/examples/pytorch/token-classification/run_ner_no_trainer.py#L601
I think modifying it this way would be better.
```python
    true_predictions = [
        [label_list[p] for (p, l) in zip(prediction, label) if p != -100]
        for prediction, label in zip(predictions, labels)
    ]
```