1. sudo apt update
2. sudo apt install -y build-essential tk-dev libncurses5-dev libncursesw5-dev libreadline6-dev libdb5.3-dev libgdbm-dev libsqlite3-dev libssl-dev libbz2-dev libexpat1-dev liblzma-dev zlib1g-dev libffi-dev
3. wget https://www.python.org/ftp/python/3.6.8/Python-3.6.8.tgz
4. sudo tar zxf Python-3.6.8.tgz
5. cd Python-3.6.8
6. sudo ./configure
7. sudo make -j 4
8. sudo make altinstall