命令地址:https://pytorch.org/get-started/previous-versions/
举例:已经装了cuda10,则:pip install torch==1.2.0 torchvision==0.4.0 -f https://download.pytorch.org/whl/torch_stable.html
安装内容:torch torchvision numpy pillow six
依赖关系:numpy->torch
pillow->torchvision
six->torchvision