Adding a Ball

The ball is simpler than you think.

First, at the top of your file, import the random package. It is pre-installed into Python.

import random

Next, create a class below the Paddle class.

class Ball(Entity):
    def __init__(self, x, y):
        super().__init__(sbox, 20, 20, x, y)
        self.reset() # will create function later

Now, let's add the reset function.

    def reset(self):
        self.center()
        self.h_dir = random.choice((-1, 1)) # backwards or forwards
        self.v_dir = random.choice((-1, 1)) # up or down

And finally, a movement function.

    def ball_movement(self, delta):
        self.x += 250 * self.h_dir * delta
        self.y += 250 * self.v_dir * delta

        if self.y <= 2 or self.y >= sbox.height - 20:
            self.v_dir *= -1
        if self.x <= 0:
            self.reset()
        elif self.x >= sbox.width:
            self.reset()

Now, you can create a Ball object after the player.

player = Paddle(50, 0)
player.center_y()

ball = Ball(0, 0)

And, in your update function, call the ball.ball_movement function.

@sbox.addUpdater
def update(delta):
    player.player_movement(delta)
    ball.ball_movement(delta)

Make sure to draw your ball to the screen, like how we did with the player.

Now, run your project!

Ball moving to the left.

Let's add collision and the enemy player now!