Method make_iterator

verl/verl/protocol.py:450–487

r"""Make an iterator from the DataProto. This is built upon that TensorDict can be used as a normal Pytorch dataset. See https://pytorch.org/tensordict/tutorials/data_fashion for more details. Args: mini_batch_size (int): mini-batch size when iterating the dataset. We r

(self, mini_batch_size, epochs, seed=None, dataloader_kwargs=None)

        return self

    def make_iterator(self, mini_batch_size, epochs, seed=None, dataloader_kwargs=None):
        r"""Make an iterator from the DataProto. This is built upon that TensorDict can be used as a normal Pytorch
        dataset. See https://pytorch.org/tensordict/tutorials/data_fashion for more details.


        Args:
            mini_batch_size (int): mini-batch size when iterating the dataset. We require that ``batch.batch_size[0] % mini_batch_size == 0``.
            epochs (int): number of epochs when iterating the dataset.
            dataloader_kwargs (Any): internally, it returns a DataLoader over the batch. The dataloader_kwargs is the kwargs passed to the DataLoader.

        Returns:
            Iterator: an iterator that yields a mini-batch data at a time. The total number of iteration steps is ``self.batch.batch_size * epochs // mini_batch_size``
        """
        assert self.batch.batch_size[0] % mini_batch_size == 0, f"{self.batch.batch_size[0]} % {mini_batch_size} != 0"
        # we can directly create a dataloader from TensorDict
        if dataloader_kwargs is None:
            dataloader_kwargs = {}

        if seed is not None:
            generator = torch.Generator()
            generator.manual_seed(seed)
        else:
            generator = None

        assert isinstance(dataloader_kwargs, Dict)
        train_dataloader = DataLoader(dataset=self,
                                      batch_size=mini_batch_size,
                                      collate_fn=collate_fn,
                                      generator=generator,
                                      **dataloader_kwargs)

        def get_data():
            for _ in range(epochs):
                for d in train_dataloader:
                    d.meta_info = self.meta_info
                    yield d

        return iter(get_data())

    def chunk(self, chunks: int) -> List['DataProto']:
        """Split the batch among dim=0 into chunks. The meta_info is passed to each DataProto after split.