Solved by svd3 in post #2 
              
              
                No torch.split takes “size” of chunk/chunks not how many chunks. 
Do this: 
a = torch.randn(50, 80) #tensor of size 50 x 80
b = torch.split(a, 40, dim=1) # it returns a tuple
b = list(b) # convert to list if you want