def __call__()

in training/run_distillation.py [0:0]


    def __call__(self, features: List[Dict[str, Union[List[int], np.ndarray]]]) -> Dict[str, np.ndarray]:
        # split inputs and labels since they have to be of different lengths and need
        # different padding methods

        # dataloader returns a list of features which we convert to a dict
        input_features = {"input_features": [feature["input_features"] for feature in features]}
        label_features = {"input_ids": [feature["labels"] for feature in features]}

        # reformat list to dict and set to pytorch format
        batch = self.processor.feature_extractor.pad(
            input_features,
            padding=self.input_padding,
            return_tensors="pt",
        )

        labels_batch = self.processor.tokenizer.pad(
            label_features,
            max_length=self.max_target_length,
            padding=self.target_padding,
            return_tensors="pt",
        )

        # shift labels to the right to get decoder input ids
        labels = labels_batch["input_ids"]
        decoder_input_ids = labels[:, :-1]
        labels = labels[:, 1:]
        labels_mask = labels_batch.attention_mask[:, 1:]

        # replace padding with -100 to ignore correctly when computing the loss
        labels = labels.masked_fill(labels_mask.ne(1), -100)

        # replace initial prompt tokens with -100 to ignore correctly when computing the loss
        bos_index = torch.argmax((labels == self.decoder_start_token_id).long(), dim=1)
        bos_index = torch.where(bos_index > 0, bos_index + 1, bos_index)
        prompt_mask = torch.arange(labels.shape[1]) < bos_index[:, None]
        labels = torch.where(prompt_mask, -100, labels)

        batch["labels"] = labels
        batch["decoder_input_ids"] = decoder_input_ids

        return batch