我的Pygame中cake类的__init__方法有何问题？如何修正？

Here are the key issues in your code and their solutions:

1. Pygame Initialization Order #

pygame.init() must be called before any other pygame operations (like creating the display screen). Move it to the top of your code, right after imports.

2. Invalid Arguments in pygame.transform.scale #

The scale function expects a tuple of integers, but you passed ([width], 80) (a list inside a tuple). Replace [width] with width to make it (width, 80).

3. Incorrect Rect Attribute Assignment #

self.rect.bottom is a single integer (the y-coordinate of the rect's bottom edge). You tried to assign a tuple (750, [pos_y]), which is invalid. Since you want to position the pancake's midbottom at (750, pos_y), use self.rect.midbottom = (750, pos_y) instead. Also, [pos_y] is unnecessary—just use the integer pos_y.

4. Sprite Image Attribute Mismatch #

Your Sprite subclass needs a self.image attribute (the surface to draw). You stored the scaled pancake in self.pancake instead of updating self.image. Assign the scaled surface directly to self.image.

Corrected Code #

import pygame
from sys import exit

pygame.init()  # Moved to top of execution

num = 3

class Cake(pygame.sprite.Sprite):  # Follow Python CamelCase class naming convention
    def __init__(self, pos_y, width):
        super().__init__()  # Modern way to call parent constructor
        original_image = pygame.image.load('Pancake.png').convert_alpha()
        self.image = pygame.transform.scale(original_image, (width, 80))  # Assign scaled image to required Sprite attribute
        self.rect = self.image.get_rect()
        self.rect.midbottom = (750, pos_y)  # Correctly position the sprite's midbottom

screen = pygame.display.set_mode((1500, 800))
pygame.display.set_caption('Pancake House')
clock = pygame.time.Clock()
background = pygame.Surface((2000, 1000))
background.fill('#96e2fc')

pancake = Cake(550, 200)
pancakes = pygame.sprite.GroupSingle()
pancakes.add(pancake)

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            exit()

    screen.blit(background, (0, 0))
    pancakes.draw(screen)

    pygame.display.update()
    clock.tick(60)

Additional Notes #

• super().__init__() is preferred over directly calling pygame.sprite.Sprite.__init__(self) as it works better with inheritance hierarchies.
• The class name was renamed to Cake to follow standard Python class naming conventions.
• The original image is stored in a temporary variable to avoid overwriting it before scaling.

内容的提问来源于stack exchange，提问作者AJAI ARJUN G BTech_ME