If we have a dataloader
train_loader = torch.utils.data.DataLoader(trainset_imoprt, batch_size=200, shuffle=True)
semi_loader = torch.utils.data.DataLoader(trainunl_imoprt, batch_size=200, shuffle=True)
valid_loader = torch.utils.data.DataLoader(validset_import, batch_size=200, shuffle=True)

How do we apply a transform to it? Like saying train_loader.dataset.transform = transform does nothing?