Automatic device transfer converts namedtuples into regular tuples

[lakshmi-speak]

🐛 Bug

In the latest version of the utilities library, automatic device transfer converts namedtuples into regular tuples, causing loss of attribute access provided by the namedtuple.

To Reproduce

from collections import namedtuple
import torch
from pytorch_lightning import LightningModule, Trainer

Batch = namedtuple("Batch", ["features", "targets"])

class SimpleModule(LightningModule):
    def __init__(self):
        super().__init__()
        self.linear = torch.nn.Linear(5, 1)
        
    def forward(self, batch):
        print(type(batch))
        print(batch.features)
        return self.linear(batch.features)

    def training_step(self, batch, batch_idx):
        return self(batch)

    def train_dataloader(self):
        features = torch.randn(10, 5)
        targets = torch.randint(0, 1, (10,))
        dataset = [Batch(features[i], targets[i]) for i in range(10)]
        return torch.utils.data.DataLoader(dataset, batch_size=1)
    
    def configure_optimizers(self):
        return torch.optim.Adam(self.parameters(), lr=1e-3)

model = SimpleModule()
trainer = Trainer(fast_dev_run=True)
trainer.fit(model)

This script fails with attribute error AttributeError: 'tuple' object has no attribute 'features', when the library version is 0.10.0 and runs without errors on 0.9.0. The Pytorch lightning version was unchanged, 2.1.2 for both.

Additional context

Environment details

• PyTorch Version (e.g., 1.0): 2.1.1+cu121
• OS (e.g., Linux): Ubuntu
• How you installed PyTorch (conda, pip, source): pip
• Python version: 3.10.13
• CUDA/cuDNN version: 12.2

This happened for both single GPU and multi GPU run with DDP. This was a bit of work to track down since the pinned pytorch_lightning version was unchanged.
This is the exact same as a previous lightning issue, although that one seems to have been due to PyTorch?

[carmocca]

Hi @lakshmi-speak. Sorry for this.

I think it's best that we revert #160.

Would you like to open a PR doing that and adding your namedtuple sample as a test to https://github.com/Lightning-AI/utilities/blob/main/tests/unittests/core/test_apply_func.py?

[Borda]

@carmocca was this resolved in #210 too?