Ubuntu, how do you remove all Python 3 but not 2

EDIT: As pointed out in recent comments, this solution may BREAK your system.

You most likely don't want to remove python3.

Please refer to the other answers for possible solutions.

Outdated answer (not recommended)

sudo apt-get remove 'python3.*'

So I worked out at the end that you cannot uninstall 3.4 as it is default on Ubuntu.

All I did was simply remove Jupyter and then alias python=python2.7 and install all packages on Python 2.7 again.

Arguably, I can install virtualenv but me and my colleagues are only using 2.7. I am just going to be lazy in this case :)

Removing Python 3 was the worst thing I did since I recently moved to the world of Linux. It removed Firefox, my launcher and, as I read while trying to fix my problem, it may also remove your desktop and terminal! Finally fixed after a long daytime nightmare. Just don't remove Python 3. Keep it there!

If that happens to you, here is the fix:

https://askubuntu.com/q/384033/402539

https://askubuntu.com/q/810854/402539

First of all, don't try the following command as suggested by Germain above.

   `sudo apt-get remove 'python3.*'`

In Ubuntu, many software depends upon Python3 so if you will execute this command it will remove all of them as it happened with me. I found following answer useful to recover it.

https://askubuntu.com/questions/810854/i-deleted-package-python3-on-ubuntu-and-i-have-lost-dashboard-terminal-and-un

If you want to use different python versions for different projects then create virtual environments it will be very useful. refer to the following link to create virtual environments.

Creating Virtual Environment also helps in using Tensorflow and Keras in Jupyter Notebook.

https://linoxide.com/linux-how-to/setup-python-virtual-environment-ubuntu/