CentOS7 に Python3.6をインストールする方法です。
curl -O -L https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
curl -O -L https://centos7.iuscommunity.org/ius-release.rpm
sudo rpm -ivh epel-release-latest-7.noarch.rpm ius-release.rpm
sudo yum install python36u python36u-libs python36u-devel python36u-pip