python3x-installation-guide-links-on-Ubunto- https://www.youtube.com/watch?v=MfkP6aYsHcg https://serverfault.com/questions/918335/best-way-to-run-python-3-7-on-ubuntu-16-04-which-comes-with-python-3-5 https://askubuntu.com/questions/229589/how-to-make-a-file-e-g-a-sh-script-executable-so-it-can-be-run-from-termina