How do I install python 3.6.5 on my Ubuntu 19.10 that already contains python 3.7.5?

Question

I will accept two possible solutions:

1. Both versions are installed side by side.
2. 3.7.5 is removed and 3.6.5 is then installed.

Answer 1

For this you can use pyenv.

https://realpython.com/intro-to-pyenv/

If you have installed all packages and dependencies you can install different version like this:

pyenv install -v 3.6.5