---
title: data
description: Unpack a batch to find a torch.Tensor.
canonical: >-
  https://lightning.ai/docs/pytorch/stable/optional-api/api/lightning.pytorch.utilities.data
---
# data {#data}

Functions

- [`extract_batch_size`](#lightning.pytorch.utilities.data.extract_batch_size) — Unpack a batch to find a torch.Tensor.
- [`has_len_all_ranks`](#lightning.pytorch.utilities.data.has_len_all_ranks) — Checks if a given object has __len__ method implemented on all ranks.

### `lightning.pytorch.utilities.data.extract_batch_size(batch)` {#lightning.pytorch.utilities.data.extract_batch_size}

Unpack a batch to find a `torch.Tensor`.

Return type:

[`int`](https://docs.python.org/3/builtins/functions.html#int "(in Python v3.15)")

Returns:

`len(tensor)` when found, or `1` when it hits an empty or non iterable.

### `lightning.pytorch.utilities.data.has_len_all_ranks(dataloader, strategy, allow_zero_length_dataloader_with_multiple_devices=False)` {#lightning.pytorch.utilities.data.has_len_all_ranks}

Checks if a given object has `__len__` method implemented on all ranks.

Return type:

`TypeGuard`\[[`Sized`](https://docs.python.org/3/library/collections.abc.html#collections.abc.Sized "(in Python v3.15)")\]

---

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- Parent: [Api](/docs/pytorch/2.6.6/optional-api/api.md)