I have uninstalled python 3.4 and python 3.5 by mistakenly. After Reboot, I have faced that problem. I didn't reach anything like terminal, menu or another bar. Only I can open a folder and reach to folders with GUI. How to fix that problem? Any help would be appreciated. Thanks in advance.
You may be able to get a working terminal by pressing Ctrl + Alt + F1 (Actually, any F-Key from 1 to 6 should work).
If you get a Terminal, you should be able to reinstall the appropriate python package via apt.
Also, it might be worth it to check first if you can fix it by installing the ubuntu-desktop metapackage, which contains some of the vital parts of your system:
sudo apt install ubuntu-desktop
