In the below code , I see that we are loading the data into the variable “trainloader” and iterating through the same. In the below example, the code assumes that there are two columns of data , images & labels respectively. How do I check the shape  and column headers in the data “trainloader” .  Any help is much appreciated.
Download and load the training data
trainset = datasets.MNIST('~/.pytorch/MNIST_data/', download=True, train=True, transform=transform)
trainloader = torch.utils.data.DataLoader(trainset, batch_size=64, shuffle=True)


dataiter = iter(trainloader)
images, labels = dataiter.next()
print(type(images))
print(images.shape)
print(labels.shape)