I have made an object controlled with arrow keys. When I move it to the edge of the pygame screen, the object moves off the screen. I was wondering how to keep the object on the screen. Any suggestions?
On each handle of the input, check if the object's target x position plus its width exceeds the width of the canvas or if it is less than 0. Deny the movement if so. 
Repeat for the y coordinate and the height.
In pygame how to make an object controlled with arrow keys not move of the edge of the screen