Solved by robo in post #3 
              
              
                Thanks,the problem has been soloved.  I installed python3.7 before anaconda, so there is the problem that python3.7 cannot use Torch and torchvision. 
because of the python3.7, when I install torchvision using  ‘pip install --no-deps torchvision’, torchvision seems not install correctly with anacond…