Why is the sprite not moving? [duplicate] - pygame

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Why is my PyGame application not running at all?
(2 answers)
Closed 1 year ago.
I am currently programming a pygame game where you move a spaceship around the screen. Currently, I have got to the part where I made the spaceship and tried to make it move. However, when I try to move the spaceship around, the spaceship doesn't move!
Here is my current code:
import pygame
pygame.init()
screen = pygame.display.set_mode((800, 500))
screen.fill((255, 255, 255))
class Spaceship(pygame.sprite.Sprite):
def __init__(self, s, x, y):
pygame.sprite.Sprite.__init__(self)
self.screen = s
self.x, self.y = x, y
self.image = pygame.image.load("C:/eqodqfe/spaceship.png")
self.image = pygame.transform.scale(self.image, (175, 175))
self.rect = self.image.get_rect()
self.rect.center = (self.x, self.y)
def update(self):
self.rect.center = (self.x, self.y)
spaceship = Spaceship(screen, 400, 400)
screen.blit(spaceship.image, spaceship.rect)
running = True
while running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
key = pygame.key.get_pressed()
if key[pygame.K_a]:
spaceship.x -= 5
elif key[pygame.K_d]:
spaceship.x += 5
elif key[pygame.K_w]:
spaceship.y += 5
elif key[pygame.K_s]:
spaceship.y -= 5
spaceship.update()
pygame.display.update()
What is wrong with my current code?

Answer 1

You have to draw the Sprties in the application loop:
clock = pygame.time.Clock()
running = True
while running:
# handle events
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
key = pygame.key.get_pressed()
if key[pygame.K_a]:
spaceship.x -= 5
elif key[pygame.K_d]:
spaceship.x += 5
elif key[pygame.K_w]:
spaceship.y -= 5
elif key[pygame.K_s]:
spaceship.y += 5
# update the position of the object
spaceship.update()
# clear the display
screen.fill((255, 255, 255))
# draw the object
screen.blit(spaceship.image, spaceship.rect)
# update the display
pygame.display.update()
# limit frames per second
clock.tick(60)
The typical PyGame application loop has to:
handle the events by either pygame.event.pump() or pygame.event.get().
update the game states and positions of objects dependent on the input events and time (respectively frames)
clear the entire display or draw the background
draw the entire scene (blit all the objects)
update the display by either pygame.display.update() or pygame.display.flip()
limit frames per second to limit CPU usage
Furthermore I suggest to use a pygame.sprite.Group:
pygame.sprite.Group.draw() and pygame.sprite.Group.update() are methods which are provided by pygame.sprite.Group.
The former delegates the to the update mehtod of the contained pygame.sprite.Sprites - you have to implement the method. See pygame.sprite.Group.update():
Calls the update() method on all Sprites in the Group [...]
The later uses the image and rect attributes of the contained pygame.sprite.Sprites to draw the objects - you have to ensure that the pygame.sprite.Sprites have the required attributes. See pygame.sprite.Group.draw():
Draws the contained Sprites to the Surface argument. This uses the Sprite.image attribute for the source surface, and Sprite.rect. [...]
spaceship = Spaceship(screen, 400, 400)
all_sprites = pygame.sprite.Group()
all_sprites.add(spaceship)
clock = pygame.time.Clock()
running = True
while running:
clock.tick(60)
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
key = pygame.key.get_pressed()
if key[pygame.K_a]:
spaceship.x -= 5
elif key[pygame.K_d]:
spaceship.x += 5
elif key[pygame.K_w]:
spaceship.y += 5
elif key[pygame.K_s]:
spaceship.y -= 5
all_sprites.update()
screen.fill((255, 255, 255))
all_sprites.draw(screen)
pygame.display.update()