Now that we have written and tested the code for the paddles, we need to write code to move the ball. We will be changing the location of the ball with some of our code, and we will create something called collision detection.
First, we need to be constantly calculating the x and y coordinates of the ball based on the velocity of the ball that we set in the global variables. This allows us to make constant updates as long as we are playing the game. To make sure that the x and y coordinates of the ball update as the ball moves, you will type the following lines of code, starting from line 74:
# location of ball is updated ball_x += ball_xv ball_y += ball_yv