python外星人入侵代码提示has no attri_【Python】pygame 外星人入侵, 出现AttributeError, 但是找不到错误？...

《python 编程：从入门到实践》书中例子：外星人入侵,在飞船可以左右移动下，子弹设置好，每次按空格键都会出现： (使用python2.7)

AttributeError: ‘Bullet’ object has not attribute ‘draw_bullet’

检查了实参或形参顺序，但还是找不到。

麻烦各位大佬了！！

代码：

一、alien_invasion.py

import pygame

from pygame.sprite import Group

from settings import Settings

from ship import Ship

import game_functions as gf

def run_game():

# 初始化游戏并创建屏幕

pygame.init()

ai_settings = Settings()

screen = pygame.display.set_mode(

(ai_settings.screen_width, ai_settings.screen_height))

pygame.display.set_caption("Alien Invasion")

#创建一艘飞船

ship = Ship(ai_settings, screen)

#创建一个用于存储子弹的编组

bullets = Group()

#开始游戏主循环

while True:

gf.check_events(ai_settings, screen, ship, bullets)

#监视键盘和鼠标事件

ship.update()

bullets.update()

gf.update_screen(ai_settings, screen, ship, bullets)

run_game()

二、bullet.py

import pygame

from pygame.sprite import Sprite

class Bullet(Sprite):

#一个对飞船发射的子弹进行管理的类

def __init__(self, ai_settings, screen, ship):

#在飞船所处的位置创建一个子弹对象

super(Bullet, self).__init__()

self.screen = screen

#在(0,0)处创建一个表示子弹的矩形，再设置正确的位置

self.rect = pygame.Rect(0, 0, ai_settings.bullet_width,

ai_settings.bullet_height)

self.rect.centerx = ship.rect.centerx

self.rect.top = ship.rect.top

#存储用小数表示的子弹位置

self.y = float(self.rect.y)

self.color = ai_settings.bullet_color

self.speed_factor = ai_settings.bullet_speed_factor

def update(self):

#向上移动子弹

#更新表示子弹位置的小数值

self.y -= self.speed_factor

#更新表示子弹的rect位置

self.rect.y = self.y

def draw_bullet(self):

#在屏幕上绘制子弹

pygame.draw.rect(self.screen, self.color, self.rect)

三、game_functions.py

import sys

import pygame

from bullet import Bullet

def check_keydown_events(event, ai_settings, screen, ship, bullets):

#响应按键

if event.key == pygame.K_RIGHT:

ship.moving_right = True

elif event.key == pygame.K_LEFT:

ship.moving_left = True

elif event.key == pygame.K_SPACE:

#创建一颗子弹，并将其加入到编组bullets中

new_bullet = Bullet(ai_settings, screen, ship)

bullets.add(new_bullet)

def check_keyup_events(event, ship):

#响应松开

if event.key == pygame.K_RIGHT:

ship.moving_right = False

elif event.key == pygame.K_LEFT:

ship.moving_left = False

def check_events(ai_settings, screen, ship, bullets):

#响应按键和鼠标事件

for event in pygame.event.get():

if event.type == pygame.QUIT:

sys.exit()

elif event.type == pygame.KEYDOWN:

check_keydown_events(event, ai_settings, screen, ship, bullets)

elif event.type == pygame.KEYUP:

check_keyup_events(event, ship)

def update_screen(ai_settings, screen, ship, bullets):

#更新屏幕上的图像并切换到新图像

#每次循环时都重绘屏幕

screen.fill(ai_settings.bg_color)

#在飞船和外星人后面重绘所有子弹

for bullet in bullets.sprites():

bullet.draw_bullet()

ship.blitme()

#让最近绘制的屏幕可见

pygame.display.flip()

四、settingds.py

class Settings():

#存储游戏的所有设置的类

def __init__(self):

#初始化游戏设置

#屏幕设置

self.screen_width = 1200

self.screen_height = 800

self.bg_color = (255, 255, 255)

#飞船移动速度控制

self.ship_speed_factor = 1.5

#子弹设置

self.bullet_speed_factor = 1

self.bullet_width = 3

self.bullet_height = 15

self.bullet_color = 60, 60, 60

五、ship.py

import pygame

class Ship():

def __init__(self, ai_settings, screen):

#初始化飞船并设置初始位置

self.screen = screen

self.ai_settings = ai_settings

#加载飞船图像并获取外接矩形

self.image = pygame.image.load('images/ship.bmp')

self.rect = self.image.get_rect()

self.screen_rect = screen.get_rect()

#将每艘飞船放到屏幕底部中央

self.rect.centerx = self.screen_rect.centerx

self.rect.bottom = self.screen_rect.bottom

#在飞船的新属性center中存储小数值

self.center = float(self.rect.centerx)

#移动标志

self.moving_right = False

self.moving_left = False

def update(self):

#根据移动标志调整飞船位置

#跟新飞船的center值

if self.moving_right and self.rect.right < self.screen_rect.right:

self.center += self.ai_settings.ship_speed_factor

if self.moving_left and self.rect.left > 0:

self.center -= self.ai_settings.ship_speed_factor

#根据self.center更新rect对象

self.rect.centerx = self.center

def blitme(self):

#在指定位置绘制飞船

self.screen.blit(self.image, self.rect)

回答