CentOS 7 install Python 3

CentOS 7 comes with some old version of Python 2 - which is going EOL in a couple of years.

Also, Django recommends Python 3 https://www.djangoproject.com/download/

#this will probably install a new version of docker, and you will likely lose all your containers !!!
sudo yum -y update
#better to reboot now

sudo yum -y install https://centos7.iuscommunity.org/ius-release.rpm

sudo yum -y install python36u

#check if installed
python3.6 -V

#beware! old python is still installed, if you run "python" you get the 2 version