install python 3.9 on ubuntu 18.04
python3 -V
sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt-get update
apt list | grep python3.9
sudo apt-get install python3.9
python3.9 -V
sudo apt-get install python3-pip
sudo apt install python3.9-distutils
sudo apt install software-properties-common
sudo apt-get install python3.9-venv
curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
python3.9 get-pip.py