Home

Overview

batchtensor is lightweight library built on top of PyTorch to manipulate nested data structure with PyTorch tensors. This library provides functions for tensors where the first dimension is the batch dimension. It also provides functions for tensors representing a batch of sequences where the first dimension is the batch dimension and the second dimension is the sequence dimension.

Motivation

Let's imagine you have a batch which is represented by a dictionary with three tensors, and you want to take the first 2 items. batchtensor provides the function slice_along_batch that allows to slide all the tensors:

>>> import torch
>>> from batchtensor.nested import slice_along_batch
>>> batch = {
...     "a": torch.tensor([[2, 6], [0, 3], [4, 9], [8, 1], [5, 7]]),
...     "b": torch.tensor([4, 3, 2, 1, 0]),
...     "c": torch.tensor([1.0, 2.0, 3.0, 4.0, 5.0]),
... }
>>> slice_along_batch(batch, stop=2)
{'a': tensor([[2, 6], [0, 3]]), 'b': tensor([4, 3]), 'c': tensor([1., 2.])}

Similarly, it is possible to split a batch in multiple batches by using the function split_along_batch:

>>> import torch
>>> from batchtensor.nested import split_along_batch
>>> batch = {
...     "a": torch.tensor([[2, 6], [0, 3], [4, 9], [8, 1], [5, 7]]),
...     "b": torch.tensor([4, 3, 2, 1, 0]),
...     "c": torch.tensor([1.0, 2.0, 3.0, 4.0, 5.0]),
... }
>>> split_along_batch(batch, split_size_or_sections=2)
({'a': tensor([[2, 6], [0, 3]]), 'b': tensor([4, 3]), 'c': tensor([1., 2.])},
 {'a': tensor([[4, 9], [8, 1]]), 'b': tensor([2, 1]), 'c': tensor([3., 4.])},
 {'a': tensor([[5, 7]]), 'b': tensor([0]), 'c': tensor([5.])})

Please check the documentation to see all the implemented functions.

API stability

While batchtensor is in development stage, no API is guaranteed to be stable from one release to the next. In fact, it is very likely that the API will change multiple times before a stable 1.0.0 release. In practice, this means that upgrading batchtensor to a new version will possibly break any code that was using the old version of batchtensor.

License

batchtensor is licensed under BSD 3-Clause "New" or "Revised" license available in LICENSE file.