Thank You @BramVanroy for the link. But the link seems to be missing modules in ~caffe2/third_party.
Thank You @ptrblck for your suggestion. I am able to change the code to suit for Python 3.
However I want to install R3D - https://github.com/facebookresearch/video-nonlocal-net/blob/master/INSTALL.md 1
In this work they had modified the files in caffe2/video and then installed caffe2 from source.
While doing the same with the current official code of Pytorch/caffe2 it seems their modified modules are not compatible with the current Pytorch/caffe2.
What are your suggestions on how to install R3D??