this is  all the error message:
Traceback (most recent call last):
  File "alexnet_try.py", line 166, in <module>
    main()
  File "alexnet_try.py", line 162, in main
    train(args, model, device, train_loader, optimizer, epoch)
  File "alexnet_try.py", line 84, in train
    output = model(data)
  File "/home/zqk/anaconda2/lib/python2.7/site-packages/torch/nn/modules/module.py", line 491, in __call__
    result = self.forward(*input, **kwargs)
  File "alexnet_try.py", line 71, in forward
    conv2 = self.conv_block2(conv1)
  File "/home/zqk/anaconda2/lib/python2.7/site-packages/torch/nn/modules/module.py", line 491, in __call__
    result = self.forward(*input, **kwargs)
  File "/home/zqk/anaconda2/lib/python2.7/site-packages/torch/nn/modules/container.py", line 91, in forward
    input = module(input)
  File "/home/zqk/anaconda2/lib/python2.7/site-packages/torch/nn/modules/module.py", line 491, in __call__
    result = self.forward(*input, **kwargs)
  File "/home/zqk/anaconda2/lib/python2.7/site-packages/torch/nn/modules/conv.py", line 301, in forward
    self.padding, self.dilation, self.groups)
RuntimeError: Expected tensor for argument #1 'input' to have the same dimension as tensor for 'result'; but 4 does not equal 2 (while checking arguments for cudnn_convolution)

the error comes from

output = model(data)


conv2 = self.conv_block2(conv1)

thus I believe there is something wrong in the forward process