Hi. I am starting with PyTorch and trying to write a simple classification code. I am using CIFAR10 dataset to train the model. This part of the code downloaded the dataset and stores it.
elif self.dataset_train == 'cifar10':
		self.dataset_train = datasets.CIFAR10(root=self.args.dataroot, train=True, download=True,
			transform=transforms.Compose([
				transforms.Scale(self.resolution),
				transforms.ToTensor(),
				transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5)),
				])
			)

And this create the dataloader.
dataloader_train = torch.utils.data.DataLoader(self.dataset_train, batch_size=self.args.batch_size,
shuffle=True, num_workers=int(self.args.nthreads))
However, when I am using the dataloader to iterate through the dataset, using just a for loop (in a different function with parameter name as dataloader) like this:
for i, data in enumerate(dataloader, 0):			
input, label = data
...

I am getting the following error:

/home/rahul/CANVAS/pytorchnet/train.py(84)train()
-> for i, data in enumerate(dataloader, 0):
(Pdb) n
–Return–
/home/rahul/CANVAS/pytorchnet/train.py(84)train()->None
-> for i, data in enumerate(dataloader, 0):
(Pdb) n
TypeError: TypeErro…nt’\n’,)
/home/rahul/CANVAS/pytorchnet/main.py(62)()
-> loss_train = trainer.train(epoch, loader_train)
(Pdb) n
–Return–
/home/rahul/CANVAS/pytorchnet/main.py(62)()->None
-> loss_train = trainer.train(epoch, loader_train)
(Pdb) n
Traceback (most recent call last):
File “main.py”, line 62, in 
loss_train = trainer.train(epoch, loader_train)
File “/home/rahul/CANVAS/pytorchnet/train.py”, line 84, in train
for i, data in enumerate(dataloader, 0):
File “/home/rahul/anaconda2/lib/python2.7/site-packages/torch/utils/data/dataloader.py”, line 212, in next
return self._process_next_batch(batch)
File “/home/rahul/anaconda2/lib/python2.7/site-packages/torch/utils/data/dataloader.py”, line 239, in _process_next_batch
raise batch.exc_type(batch.exc_msg)
TypeError: Traceback (most recent call last):
File “/home/rahul/anaconda2/lib/python2.7/site-packages/torch/utils/data/dataloader.py”, line 41, in _worker_loop
samples = collate_fn([dataset[i] for i in batch_indices])
File “/home/rahul/anaconda2/lib/python2.7/site-packages/torchvision-0.1.8-py2.7.egg/torchvision/datasets/cifar.py”, line 99, in getitem
img = self.transform(img)
File “/home/rahul/anaconda2/lib/python2.7/site-packages/torchvision-0.1.8-py2.7.egg/torchvision/transforms.py”, line 29, in call
img = t(img)
File “/home/rahul/anaconda2/lib/python2.7/site-packages/torchvision-0.1.8-py2.7.egg/torchvision/transforms.py”, line 139, in call
ow = int(self.size * w / h)
TypeError: unsupported operand type(s) for /: ‘tuple’ and ‘int’

When I try to debug using pdb, I see that inside the PyTorch’s dataloader.py file, the batch becomes an instance of ExceptionWrapper. It is not clear as exactly what am I doing wrong as I have run the same kind of loops on dataloader previously with CIFAR10. Please help!