trainutil

Simple, composable PyTorch training utilities.

• Batch: declare a batch as a dataclass and collate samples into it.
• EMA: exponential moving average you can swap into the model for evaluation.
• Metrics: weighted running means reduced across DDP ranks in one call.

Installation

pip install trainutil

Usage

Batch

@dataclass
class Batch(BaseBatch):
    coords: torch.Tensor
    name: list[str]

a = Batch.from_sample(coords=torch.randn(5, 3), name="a")
b = Batch.from_sample(coords=torch.randn(3, 3), name="b")
batch = Batch.collate([a, b])

batch.coords.shape  # (2, 5, 3)
batch.name          # ['a', 'b']
batch[1]            # Batch of size one
batch.to("cuda")    # every tensor field moves

EMA

ema = EMA(model, decay=0.999)  # averages the parameters with requires_grad

optimizer.step()
ema.update()

with ema.swap():  # model holds the EMA weights inside the block
    validate(model)

With DDP, pass the unwrapped module (model.module). ema.state_dict() uses the same keys as the model, so model.load_state_dict(ckpt["ema"], strict=False) loads the EMA weights for inference.

Metrics

metrics = MetricAccumulator()
metrics.add({"loss": loss, "lddt": lddt}, weight=batch.batch_size)

means = metrics.flush()  # weighted mean over all ranks; call on every rank
if rank == 0:
    wandb.log(means, step=step)