Pong game in Pygame

This is my first time trying OOP and I definitely made many stylistic mistakes. Please tell me how I should improve.

Controls:

• w and s for player 1

• ↑ and ↓ for player 2

The player with higher score has shorter paddle. Once the difference in score is bigger than 7, the game quits.

```
import pygame
import random

YELLOW = (255, 255, 100)
BLUE = (50, 50, 255)
RED = (255, 50, 50)
BLACK = (0, 0, 0)
WHITE = (255,255,255)
SCREEN_WIDTH = 800
SCREEN_HEIGHT = 600
PADDLE_HEIGHT = 100
done = False

class Ball(pygame.sprite.Sprite):
def __init__(self, x, y, xspeed, yspeed):
super().__init__()
self.image = pygame.Surface((16,16))
self.rect = self.image.get_rect()
self.x = x
self.y = y
self.rect.x = x
self.rect.y = y
pygame.draw.circle(self.image,YELLOW,(8,8),8)
self.speed_x = xspeed
self.speed_y = yspeed
self.deathcount_left = None
self.deathcount_right = None
self.walls = None
self.index = 0
def checkdeath(self):
if self.rect.xSCREEN_WIDTH:
self.deathcount_right.plus()
self.rect.x = self.x
self.rect.y = self.y
self.speed_x = random.randint(10,12)
self.speed_y = random.randint(10,12)

def update(self):
self.checkdeath()
self.rect.x += self.speed_x
wall_hit_list = pygame.sprite.spritecollide(self, self.walls, False)
if self.index == 1:
self.rect.y+=self.speed_y
self.index = 0
else:
if wall_hit_list:
self.speed_x = -self.speed_x
self.rect.y += self.speed_y
else:
self.rect.y += self.speed_y
wall_hit_list = pygame.sprite.spritecollide(self, self.walls, False)
if wall_hit_list:
self.speed_y = -self.speed_y
self.index=1

class Wall(pygame.sprit

This is a short and very incomplete list of some small things that could be done differently:

-
Be wary of initializing things to None; it can produce some annoying bugs later on where Python yells at you for using a Nonetype where it expects something else:

# In Ball
self.walls = pygame.sprite.Group()
self.deathcount_left = Score(...)
self.deathcount_right = Score(...)
...
# In Paddle
self.my_score = ball.deathcount_left
self.enemy_score = ball.deathcount_right

Alternately, you could add to the constructor for Paddle to take in 2 Scores--yours and the enemy's.

• Do you intend for anything other than Paddle to inherit from Wall? If not, you don't need Wall at all because Wall.__init__ is only ever called in Paddle.__init__. Though not totally necessary, you could do away with Wall and copy over its constructor into Paddle's, though some might cringe at the length of the result.

I'm hesitant to add any more for fear of misleading you, but OOP aside, some small stylistic notes:

• It's generally considered good practice to leave some sort of comment describing your classes/functions/etc., if only so that as your work expands you don't have to read code to figure out what a function does.

Ball.update:

• You can move self.rect.y += self.speed_y just below self.rect.x += self.speed_x--it occurs regardless of the condition.

-
Instead of using a nested if statement (if self.index == 1 etc.) you can rewrite with elif

if self.index == 1:
    self.index = 0
elif wall_hit_list:
    self.speed_x *= -1
else:
    wall_hit_list = ...
    if wall_hit_list:
        self.speed_y *= -1
        self.index = 1

StackExchange Code Review Q#96638, answer score: 5