How to make Ubuntu 18.04 LTS use python 3.7 as default?

[황병희]

> So how can I make python use version 3 (or even 3.7.8)?

In my most case, i write simple script with shebang.

As like follow: (i also use Ubuntu 18.04 LTS)
#!/usr/bin/env python3.7
# -*- coding: utf-8 -*-

Sincerely, Byung-Hee

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^고맙습니다 _救濟蒼生_ 감사합니다_^))//