def load_dataset()

in src/fairseq/fairseq/tasks/sentence_prediction.py [0:0]


    def load_dataset(self, split, combine=False, **kwargs):
        """Load a given dataset split (e.g., train, valid, test)."""
        def get_path(type, split):
            return os.path.join(self.args.data, type, split)

        def make_dataset(type, dictionary):
            split_path = get_path(type, split)

            dataset = data_utils.load_indexed_dataset(
                split_path,
                dictionary,
                self.args.dataset_impl,
                combine=combine,
            )
            return dataset

        input0 = make_dataset('input0', self.source_dictionary)
        assert input0 is not None, 'could not find dataset: {}'.format(get_path(type, split))
        input1 = make_dataset('input1', self.source_dictionary)

        if self.args.init_token is not None:
            input0 = PrependTokenDataset(input0, self.args.init_token)

        if input1 is None:
            src_tokens = input0
        else:
            if self.args.separator_token is not None:
                input1 = PrependTokenDataset(input1, self.args.separator_token)

            src_tokens = ConcatSentencesDataset(input0, input1)

        with data_utils.numpy_seed(self.args.seed):
            shuffle = np.random.permutation(len(src_tokens))

        src_tokens = maybe_shorten_dataset(
            src_tokens,
            split,
            self.args.shorten_data_split_whitelist,
            self.args.shorten_method,
            self.args.max_positions,
            self.args.seed,
        )

        dataset = {
            'id': IdDataset(),
            'net_input': {
                'src_tokens': RightPadDataset(
                    src_tokens,
                    pad_idx=self.source_dictionary.pad(),
                ),
                'src_lengths': NumelDataset(src_tokens, reduce=False),
            },
            'nsentences': NumSamplesDataset(),
            'ntokens': NumelDataset(src_tokens, reduce=True),
        }

        if self.args.add_prev_output_tokens:
            prev_tokens_dataset = RightPadDataset(
                RollDataset(src_tokens, 1),
                pad_idx=self.dictionary.pad(),
            )
            dataset['net_input'].update(
                prev_output_tokens=prev_tokens_dataset,
            )

        if not self.args.regression_target:
            label_dataset = make_dataset('label', self.label_dictionary)
            if label_dataset is not None:
                dataset.update(
                    target=OffsetTokensDataset(
                        StripTokenDataset(
                            label_dataset,
                            id_to_strip=self.label_dictionary.eos(),
                        ),
                        offset=-self.label_dictionary.nspecial,
                    )
                )
        else:
            label_path = "{0}.label".format(get_path('label', split))
            if os.path.exists(label_path):
                def parse_regression_target(i, line):
                    values = line.split()
                    assert len(values) == self.args.num_classes, \
                        f'expected num_classes={self.args.num_classes} regression target values on line {i}, found: "{line}"'
                    return [float(x) for x in values]
                dataset.update(
                    target=RawLabelDataset([
                        parse_regression_target(i, line.strip()) for i, line in enumerate(open(label_path).readlines())
                    ])
                )

        nested_dataset = NestedDictionaryDataset(
            dataset,
            sizes=[src_tokens.sizes],
        )

        if self.args.no_shuffle:
            dataset = nested_dataset
        else:
            dataset = SortDataset(
                nested_dataset,
                # shuffle
                sort_order=[shuffle],
            )

        logger.info("Loaded {0} with #samples: {1}".format(split, len(dataset)))

        self.datasets[split] = dataset
        return self.datasets[split]