Issue description

Considering the merge of Tensors and Variables, and the "removal" of Variables from the API, there are still some messages that reference Variable. This might prove to be confusing for new users starting off from 0.4.0, as they probably might not have heard of Variable.

I did a code search to find out multiple instances of this in torch/csrc/utils/python_arg_parser.h.

Code example

j = [(torch.randn(3), ) for _ in range(0, 5)]
j = torch.cat(j, dim=0)  # j is a list of tuples, the first element being a tensor.
# Error printed: TypeError: expected Variable as element 0 in argument 0, but got list

System Info

• PyTorch or Caffe2: PyTorch
• How you installed PyTorch (conda, pip, source): source (@ e6ef18d)
• Build command you used (if compiling from source): python3 setup.py build develop
• OS: Ubuntu 16.04.2
• PyTorch version: 0.5.0a0+e6e18d
• Python version: 3.5
• CUDA/cuDNN version: 8.0.44
• GPU models and configuration: GeForce 940M
• GCC version (if compiling from source): 5.4.0
• CMake version: 3.5.1