upgrade python3.5 to 3.7 ubuntu code example
Example 1: update ubuntu to python 3.85
sudo apt-get install python3.8
Example 2: change python 3.5 to 3.6 ubuntu
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.5 1
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.6 2
sudo update-alternatives --config python3
Example 3: update ubuntu to python 3.85
sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt-get update