I'm still getting around Ubuntu and the Terminal. I know a bit of Python, so I figured I could install the latest stable release of Python. When I launched python on the Terminal, it started Python 2.7.3, So I figured that Python 3.5.2 wasn't installed.
Anyway, I followed this Ask Ubuntu thread to install it, but didn't take care to read the following:
DON'T change the symlink! There are apparently many system functions that don't work properly with python3.5.
I tried this and afterwards couldn't open a terminal, software updater,...
And well, now I can't open the terminal. I'm able to use X-Term, but I really want to fix this.
I typed the following in the Terminal:
sudo rm python2 sudo rm python3
and then closed the Terminal.