蟒蛇/ pygame帮助实验室13 programarcadegames

Question

我正在通过programarcadegames实验室使用python和pygame工作，我卡住了。当我运行这段代码时，当我初始化块和玩家类时，我做错了什么。玩家类应该是它自己的类，而不是Block类的一个实例。

当我运行这个程序，我收到此错误： “块”对象有没有属性“changespeed”

import pygame 
import random 

# Define some colors 
BLACK = ( 0, 0, 0) 
WHITE = (255, 255, 255) 
RED = (255, 0, 0) 
BLUE = (0, 0, 255) 

class Block(pygame.sprite.Sprite): 

    def __init__(self, color, width, height): 
     """ Constructor. Pass in the color of the block, 
     and its x and y position. """ 

     # Call the parent class (Sprite) constructor 
     super().__init__() 

     # Create an image of the block, and fill it with a color. 
     # This could also be an image loaded from the disk. 
     self.image = pygame.Surface([width, height]) 
     self.image.fill(color) 

     # Fetch the rectangle object that has the dimensions of the image 
     # image. 
     # Update the position of this object by setting the values 
     # of rect.x and rect.y 
     self.rect = self.image.get_rect() 

class Player (pygame.sprite.Sprite): 
    """ The class is the player-controlled sprite. """ 

    def __init__(self,x,y): 
     """Constructor function""" 
     # Call the parent's constructor 
     super().__init__() 

     # -- methods 
     # Set height, width 
     self.image = pygame.Surface([15, 15]) 
     self.image.fill(BLACK) 

     # Make our top-left corner the passed-in location. 
     self.rect = self.image.get_rect() 
     self.rect.x = x 
     self.rect.y = y 

     # -- Attributes 
     # Set speed vector 
     self.change_x = 0 
     self.change_y = 0 

    def changespeed(self, x, y): 
     """ Change the speed of the player""" 
     self.change_x += x 
     self.change_y += y 

    def update(self): 
     """ Find a new position for the player""" 
     self.rect.x += self.change_x 
     self.rect.y += self.change_y 

# Initialize Pygame 
pygame.init() 

# Set the height and width of the screen 
screen_width = 700 
screen_height = 400 
screen = pygame.display.set_mode([screen_width, screen_height]) 

# This is a list of 'sprites.' Each block in the program is 
# added to this list. The list is managed by a class called 'Group.' 
block_list = pygame.sprite.Group() 

# This is a list of every sprite. 
# All blocks and the player block as well. 
all_sprites_list = pygame.sprite.Group() 

for i in range(50): 
    # This represents a block 
    block = Block(BLACK, 20, 15) 

    # Set a random location for the block 
    block.rect.x = random.randrange(screen_width) 
    block.rect.y = random.randrange(screen_height) 

    # Add the block to the list of objects 
    block_list.add(block) 
    all_sprites_list.add(block) 

# Create a RED player block 
player = Block(BLUE, 20, 15) 
all_sprites_list.add(player) 

# Loop until the user clicks the close button. 
done = False 

# Used to manage how fast the screen updates 
clock = pygame.time.Clock() 

score = 0 

# -------- Main Program Loop ----------- 
while not done: 
    for event in pygame.event.get(): 
     if event.type == pygame.QUIT: 
      done = True 
     # Set the speed based on the key pressed 
     elif event.type == pygame.KEYDOWN: 
      if event.key == pygame.K_LEFT: 
       player.changespeed(-3, 0) 
      elif event.key == pygame.K_RIGHT: 
       player.changespeed(3, 0) 
      elif event.key == pygame.K_UP: 
       player.changespeed(0, -3) 
      elif event.key == pygame.K_DOWN: 
       player.changespeed(0, 3) 

     # Reset speed when key goes up 
     elif event.type == pygame.KEYUP: 
      if event.key == pygame.K_LEFT: 
       player.changespeed(3, 0) 
      elif event.key == pygame.K_RIGHT: 
       player.changespeed(-3, 0) 
      elif event.key == pygame.K_UP: 
       player.changespeed(0, 3) 
      elif event.key == pygame.K_DOWN: 
       player.changespeed(0, -3) 

    # Clear the screen 
    screen.fill(WHITE) 

    # Get the current mouse position. This returns the position 
    # as a list of two numbers. 
    #pos = pygame.mouse.get_pos() 

    # Fetch the x and y out of the list, 
     # just like we'd fetch letters out of a string. 
    # Set the player object to the mouse location 
    #player.rect.x = pos[0] 
    #player.rect.y = pos[1] 

    # See if the player block has collided with anything. 
    blocks_hit_list = pygame.sprite.spritecollide(player, block_list, True) 

    # Check the list of collisions. 
    for block in blocks_hit_list: 
     score += 1 
     print(score) 

    # This calls update on all the sprites 
    all_sprites_list.update() 

    # Draw all the spites 
    all_sprites_list.draw(screen) 

    # Go ahead and update the screen with what we've drawn. 
    pygame.display.flip() 

    # Limit to 60 frames per second 
    clock.tick(60) 

pygame.quit() 

Answer 1

这里的问题：player = Block(BLUE, 20, 15)。 player是Block实例，不是Player实例，块没有changespeed方法。