I'm trying to apply OOP in this bouncing ball code in order to have multiple
balls bouncing around the screen. The objective of this code is to create a
method called settings, which controls all the settings for the screen and the
bouncing behaviour of multiple balls, under the class Ball. However, I keep on
getting errors related to attributes (e.g., speed). I'm new to OOP in Python so
your help will be much appreciated. Thanks in advance.
import pygame
import random
import sys
pygame.init()
class Ball:
def __init__(self, X, Y):
self.velocity = [1,1]
self.ball_image = pygame.image.load ("ball.jpg")
self.ball_boundary = self.ball_image.get_rect ()
self.black = [0,0,0]
self.width = 800
self.height = 600
self.num = 8
self.X = random.randint(0, self.width)
self.Y = random.randint(0, self.height)
def settings(self):
#X = random.randint(0, self.width)
#Y = random.randint(0, self.height)
clock = pygame.time.Clock()
size = self.width, self.height
screen = pygame.display.set_mode(size)
ball_boundary = self.ball_image.get_rect()
speed = self.velocity
pic = self.ball_image
pygame.display.set_caption("Balls")
num_balls = self.num
ball_list = []
for i in range(num_balls):
ball_list.append( Ball(random.randint(10,
self.width-10),random.randint(10, self.height-10)) )
while 1:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit(0)
screen.fill(self.black)
for balls in ball_list:
if balls.ball_boundary.left < 0 or balls.ball_boundary.right >
self.width:
balls.speed[0] = -balls.speed[0]
if balls.ball_boundary.top < 0 or balls.ball_boundary.bottom >
self.height:
balls.speed[1] = -balls.speed[1]
balls.ball_boundary = balls.ball_boundary.move (self.velocity)
screen.blit (balls.ball_image, balls.ball_boundary)
pygame.display.flip()
play = Ball(random.randint(0, 800), random.randint(0, 600))
play.settings()
Message File Name Line Position
Traceback
<module> C:\....\Multiple_balls_TC.py 63
settings C:\....\Multiple_balls_TC.py 56
AttributeError: Ball instance has no attribute 'speed'
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