TypeError：unbound method sprite（）

Question

对于我的高级高级计算课程，我需要做一个项目，地雷正在制造太空入侵者，之前我从未使用过python，而且我对目前为止的进度感到非常满意，不过我最近遇到了一个我不知道如何处理的错误。代码如下。

import pygame 
import random 
import sys 
# --- constants --- (UPPER_CASE names) 

WHITE = (255, 255, 255) 
BLACK = ( 0, 0, 0) 
RED = (255, 0, 0) 
GREEN = ( 0, 255, 0) 
BLUE = ( 0, 0, 255) 
ORANGE = (255, 255, 0) 
YELLOW = ( 0, 255, 255) 

DISPLAY_WIDTH = 720 
DISPLAY_HEIGHT = 720 

FPS = 60 

# --- classes --- (CamelCase names) 

class Player(pygame.sprite.Sprite): 
    def __init__(self): 
     pygame.sprite.Sprite.__init__(self) 
     self.image = pygame.image.load("images\\user1.gif").convert() 
     self.image = pygame.transform.scale(self.image, (50, 50)) 
     self.rect = self.image.get_rect() 
     self.speed_x = 0 

    def update(self): 
     self.speed_x = 0 
     keystate = pygame.key.get_pressed() 
     if keystate[pygame.K_LEFT]: 
      self.speed_x = -7 
     if keystate[pygame.K_RIGHT]: 
      self.speed_x = 7 
     self.rect.x += self.speed_x 
     if self.rect.right > DISPLAY_WIDTH: 
      self.rect.right = DISPLAY_WIDTH 
     if self.rect.left < 0: 
      self.rect.left = 0 

    def shoot(self): 
     bullet = Bullet(self.rect.centerx, self.rect.top) 
     all_sprites.add(bullet) 

class Mob(pygame.sprite.Sprite): 
    def __init__(self): 
     pygame.sprite.Sprite.__init__(self) 
     self.image = pygame.image.load("images\\enemy1.gif").convert() 
     self.image = pygame.transform.scale(self.image, (50, 50)) 
     self.rect = self.image.get_rect() 
     self.speed_x = 0 
     self.rect.x = random.randrange(0, DISPLAY_WIDTH - self.rect.width) 
     self.rect.y = random.randrange(-500, -40) 
     self.speedy = random.randrange(5, 11) 

    def update(self): 
      self.rect.y +=self.speedy 
      if self.rect.top > DISPLAY_HEIGHT + 10: 
       self.rect.x = random.randrange(0, DISPLAY_WIDTH - self.rect.width) 
       self.rect.y = random.randrange(-100, -40) 
       self.speed_y = random.randrange(5, 11) 

class Bullet(pygame.sprite.Sprite): 

    def __init__(self, x, y): 
     pygame.sprite.Sprite.__init__(self) 
     self.image = pygame.image.load("images\\laser1.gif").convert() 
     self.image = pygame.transform.scale(self.image, (15, 25)) 
     self.rect = self.image.get_rect() 
     self.rect.bottom = y 
     self.rect.centerx = x 
     self.speed_y = -20 

    def update(self): 
     self.rect.y += self.speed_y 
     if self.rect.bottom < 0: 
      self.kill() 

# --- functions --- (lower_case names) 

# empty 

# --- main --- (lower_case names) 

# - init - 

pygame.init() 
pygame.mixer.init() 

display = pygame.display.set_mode((DISPLAY_WIDTH, DISPLAY_HEIGHT)) 
display_rect = display.get_rect() 

# - objects and groups - 

all_sprites = pygame.sprite.Group() 
mobs = pygame.sprite.Group() 
bullet_group = pygame.sprite.Group 
player = Player() 
player.rect.center = ((DISPLAY_WIDTH/2), DISPLAY_HEIGHT/1.2) 

all_sprites.add(player) 

for z in range(8): 
    mob = Mob() 
    mobs.add(mob) 
    all_sprites.add(mob) 

background = pygame.image.load("images\\background.jpg") 
background = pygame.transform.scale(background, (DISPLAY_WIDTH, DISPLAY_HEIGHT)) 

# - other - 

pygame.mixer.music.load("audio\\soundtrack.mp3") 
pygame.mixer.music.play(-1) 
pygame.mixer.music.set_volume(0.4) 

# - mainloop - 

crashed = False 
clock = pygame.time.Clock() 



while not crashed: 

    # - checks for a hit - 
    col = pygame.sprite.spritecollideany(player, mobs) 
    if col: 
     sys.exit() 

    col = pygame.sprite.groupcollide(mobs, bullet_group, True, True) 

    # - events - 
    for event in pygame.event.get(): 
     if event.type == pygame.QUIT: 
      crashed = True 
     elif event.type == pygame.KEYDOWN: 
      if event.key == pygame.K_SPACE: 
       player.shoot() 

     print(event) 

# - updates (without draws) - 

    all_sprites.update() 

# - draws (without updates) - 

    display.blit(background, (0, 0)) 

    all_sprites.draw(display) 

    pygame.display.update() 

# - FPS - 

    clock.tick(FPS) 

# - end - 
pygame.quit() 

这是我收到的错误消息，任何帮助将是伟大的，谢谢。

C:\Python27\python.exe "C:/Users/Iain/Desktop/Computing Project/Galaxian.py" 
Traceback (most recent call last): 
    File "C:/Users/Iain/Desktop/Computing Project/Galaxian.py", line 132, in <module> 
    col = pygame.sprite.groupcollide(mobs, bullet_group, True, True) 
    File "C:\Python27\lib\site-packages\pygame\sprite.py", line 1382, in groupcollide 
    c = SC(s, groupb, dokillb, collided) 
    File "C:\Python27\lib\site-packages\pygame\sprite.py", line 1339, in spritecollide 
    for s in group.sprites(): 
TypeError: unbound method sprites() must be called with Group instance as first argument (got nothing instead) 

Process finished with exit code 1 

Answer 1

“未绑定方法”是从类中获取的方法对象。当被调用时，它需要传递给它的类的一个实例。

“绑定方法”是绑定到类的实例的方法。它可以被称为“正常”，因为它已经有了这个实例。

就你而言，你有一个简单的错字。你有一个未绑定的方法，但它应该是一个绑定的方法。该消息是误导性的，因为真正的问题是你传递给pygame的参数不正确。

在您的程序的132行上，您可以拨打groupcollide。您提供的一个参数是名为bullet_group的变量。

问题的根本原因是这一行：

bullet_group = pygame.sprite.Group 

你错过了括号，所以其结果是名bullet_group指类pygame.sprite.Group。您只需添加括号来调用该类，以创建它的一个实例。

bullet_group = pygame.sprite.Group() 

你前面的线mobs和all_sprites上正确这样做。