how to make a sprite bounce of the edges of the window in pygame

Question

So far I have my program bouncing from left to right, but now I want to have in bounce of the walls. How can I get to that?

delta = 5
u = 1 # x coordinate

u += delta
if u >= 440: #480 is the window size, I have it stopping at 440
   delta = -5 #Go back by 5
elif u < 0:
   delta = 5 #Go up by 5

Bigger Snip it of code, It has the solution but the sprite goes off the screen, To Run the code make sure you have a picture called "bird.png" or change the picture:

import pygame
import random

class mySprite(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load("bird.png")
        self.rect = self.image.get_rect()
##        slef.rect(50,50,self.image.get_width(), self.image.get_height())

    def update(self,x,y):
        self.rect.x = x
        self.rect.y = y

class newSprite(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load("ball.png")
        self.rect = self.image.get_rect()

    def update(self,x,y):
        self.rect.x = x
        self.rect.y = y

class otherSprite(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load("bird.png")
        self.rect = self.image.get_rect()

    def update(self,x,y):
        self.rect.x = x
        self.rect.y = y

def main():
    """ Set up the game and run the main game loop """
    pygame.init() # prepare the pygame module for use
    surfaceSz = 480 # Desired physical surface size, in pixels.
    # Create surface of (width, height), and its window.
    main_surface = pygame.display.set_mode((surfaceSz, surfaceSz))

    small_rect = (300, 200, 150, 90)
    some_color = (255,0,0)
    main_surface.fill((0,200,255))

    s = mySprite()
    all_sprites = pygame.sprite.Group()

    s.add(all_sprites)

    delta_x = 5
    delta_y = 5
    u = 1 # x coord
    v = 1 # y coord

    clock = pygame.time.Clock()
    while True:
        ev = pygame.event.poll() # look for any event
        if ev.type == pygame.QUIT: # window close button clicked?
            break # ... leave game loop

        main_surface.fill((0,200,255))

        #u += delta
        #if u >= 440:
        #    delta = -5
        #elif u < 0:
        #    delta = 5

        u += delta_x
        v += delta_y
        if (v >=440): #assuming your y axis is 440 pixels
            delta_y = -5
        elif v<=0 :
            delta_y = 5

        if u >= 440: #440 pixels u have
            delta = -5
        elif u < 0:
            delta = 5 #Go up by 5


        all_sprites.update(u,50)
        pos =(random.randint(0, surfaceSz), random.randint(0, surfaceSz))
        all_sprites.draw(main_surface)

        # Now the surface is ready, tell pygame to display it!
        pygame.display.flip()
        clock.tick(60)

    pygame.quit() # once we leave the loop, close the window.

main()

Answer 1

here's a moving bird/ball that is bouncing off the walls, first of all you need only one type of class for sprites, simply create different instances with different images. Hope it helps

import sys, pygame, random

SIZE = width, height = 640, 480
SPEED = [2, 2]
black = 0, 0, 0

class mySprite(pygame.sprite.Sprite):
    def __init__(self, image="ball.bmp", speed=[2,2]):

        pygame.sprite.Sprite.__init__(self)
        self.speed = speed
        self.image = pygame.image.load(image)
        self.rect = self.image.get_rect()

    def update(self):
        global SIZE
        #i used 110 px because it's the size of the image, but it's better to use the rect property of the pygame
        if (self.rect.x <0) or (self.rect.x > 640-110):
            self.speed[0] *= -1
        if (self.rect.y<0) or (self.rect.y > 480-110):
            self.speed[1] *= -1

        self.rect.x =self.rect.x + self.speed[0]
        self.rect.y =self.rect.y + self.speed[1]

#OR:        self.rect = self.rect.move(self.speed)

    def draw(self, screen):
        screen.blit(self.image, self.rect)


#    
pygame.init()
screen = pygame.display.set_mode(SIZE)

iaka = mySprite()

while 1:
    for event in pygame.event.get():
        if event.type == pygame.QUIT: sys.exit()

    screen.fill(black)
    iaka.draw(screen)
    iaka.update()
    pygame.display.flip()

Answer 2

make a y coordinate as well

delta_y = 5
delta_x = 5
u = 1 # the x coordinate
v = 1 # the y coordinate

u +=delta_x    
v +=delta_y

if (v >=300): #assuming your y axis is 300 pixels 
    delta_y = -5
elif v<=0 :
    delta_y = 5

if u >= 440: #440 pixels u have
    delta_x = -5 
elif u < 0:
    delta_x = 5 #Go up by 5