how to change python 2.7 to 3.7 in ubuntu code example

Example 1: update python ubuntu

sudo apt-get update && sudo apt-get upgrade
sudo apt-get install python3.7

Example 2: update python ubuntu

$ sudo apt update -y
$ sudo apt install python3.7

Example 3: 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