pip doesn't work after Python upgrade

[bowlofred]

Never change the system python.

What do you mean by "system python" ?

Whatever /usr/bin/python or /usr/bin/python3 points to. It's likely that system components refer to that path and may not be able to cope with changes.

You should be able to add a new python without modifying /usr/bin/python*.

It's installed alongside: I can point python3 either to 3.6.9 either to 3.10.
When python3 points to 3.10, I can't use gnome-terminal which I got used to.

Okay. Don't point /usr/bin/python to a different version.

... put it first in your PATH

Can you elaborate, please.

Either create a venv that points at the new python and activate it, or modify your login script (sometimes .bashrc, sometimes .profile or .bash_login) and modify the PATH so that the new python bin is in it. Maybe something like PATH=/usr/local/python-3.10/bin:${PATH} (but with whatever path is appropriate to the install.)

That lets the system components use /usr/bin/python3 to hit the original version, but you can just do python or /usr/local/python-3.10/bin/python3 (again, with the correct path) to get to the new version.