A keyboard only desktop switching already exists. The keyboard keys are Alt+tab, it brings up a menu showing the available desktop and running apps for each.
Unless you are unaware of the keyboard strokes to switch between desktops. I think perhaps a language barrier is in play here. Is that it?
Kate
Be careful here! On my system, for example, that shortcut only brings up a list of all applications, with no indication of what desktop they are on.
Tim