Install Apex with python3.xx

it will install python-only build. 

$ git clone https://github.com/NVIDIA/apex
$ cd apex
$ sudo pip3 install -v --no-cache-dir ./



for installation with all functionalities run , but it throw error for me.

$ sudo pip install -v --no-cache-dir --global-option="--cpp_ext" --global-option="--cuda_ext" ./ --user