Please follow the steps..
Step 1--
sudo yum -y install gcc openssl-devel bzip2-devel
step 2-
wget https://www.python.org/ftp/python/3.6...
Step 3 --
tar xzf Python-3.6.6.tgz
cd Python-3.6.6
./configure --enable-optimizations
sudo make altinstall
sudo ln -sfn /usr/local/bin/python3.6 /usr/bin/python3.6
step 4--
python3.6 -V