This product, made by a man named Jatin Patel, is said to have been programmed in Python so that when a key is pressed, it is transmitted to the Arduino via USB. Even the sound alone is not enough to reproduce the movement of the typewriter, winding a coil on a wooden plank and designing it to move little by little while making a typewriter sound whenever you hit the keyboard. When changing strings, it even makes a clicking sound like a typewriter. Related information can be found here.