Pygame Error: self.spritedict[spr] = surface_blit(spr.image,

Question

我正在用pygame用python 3制作一个游戏。我无法将外星人的图像显示在"屏幕"表面。

我找了几个小时，复习了这本书的基础，但我找不到问题的根源。我还研究了这里的其他问题。感谢

这是追踪：

Traceback (most recent call last):
File "alien_invasion.py", line 35, in <module>
run_game()
File "alien_invasion.py", line 33, in run_game
g_funcs.update_screen(ai_settings, ai_screen, a_ship, aliens_g, bullets)
File ...
aliens_g.draw(ai_screen)
File...
self.spritedict[spr] = surface_blit(spr.image, spr.rect)
AttributeError: 'Alien' object has no attribute 'image'

这是我的游戏模块：

import pygame
from pygame.sprite import Group
from settings import Settings
from ship import Ship
import game_function as g_funcs

def run_game():
"""Games definition with control while loop"""
#Initialize pygame, settings and screen surface
pygame.init()
ai_settings = Settings()
ai_screen = pygame.display.set_mode(
(ai_settings.screen_width, ai_settings.screen_length))
pygame.display.set_caption("Alien Invasion")
#make a ship, group of bullets, group of aliens
a_ship = Ship(ai_settings, ai_screen)
bullets = Group()
aliens_g = Group()
#Create FLEET of aliens
g_funcs.create_fleet(ai_settings, ai_screen, aliens_g)
#start the main loop for the game
while True:
g_funcs.check_events(ai_settings, ai_screen, a_ship, bullets)
a_ship.update_location()
g_funcs.update_bullet(bullets)
g_funcs.update_screen(ai_settings, ai_screen, a_ship, aliens_g, bullets)
run_game()

以下是所有功能：

import sys
import pygame
from bullet import Bullet
from alien import Alien
def check_events(ai_settings, ai_screen, a_ship, bullets):
"""Respond to keypresses and mouse events."""
#watch for keyboard and mouse events
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
elif event.type == pygame.KEYDOWN:
check_keydown_event(event, ai_settings, ai_screen, a_ship, bullets)
elif event.type == pygame.KEYUP:
check_keyup_event(event, a_ship)

def check_keydown_event(event, ai_settings, ai_screen, a_ship, bullets):
"""ONLY callable by check_events function when keydown."""
if event.key == pygame.K_RIGHT:
a_ship.moving_right = True
elif event.key == pygame.K_LEFT:
a_ship.moving_left = True
elif event.key == pygame.K_UP:
a_ship.moving_up = True
elif event.key == pygame.K_DOWN:
a_ship.moving_down = True
elif event.key == pygame.K_SPACE:
fire_bullet(ai_settings, ai_screen, a_ship, bullets)
elif event.key == pygame.K_q:
sys.exit()
def fire_bullet(ai_settings, ai_screen, a_ship, bullets):
"""Fire bullets if bullets limit is not met"""
#CREATE a new bullet INSTANCE and add it to the bullets GROUP
if len(bullets) < ai_settings.bullets_allowed:
new_bullet = Bullet(ai_settings, ai_screen, a_ship)
bullets.add(new_bullet)
def check_keyup_event(event, a_ship):
"""ONLY callable by check_events function when keyup."""
if event.key == pygame.K_RIGHT:
a_ship.moving_right = False
if event.key == pygame.K_LEFT:
a_ship.moving_left = False
if event.key == pygame.K_UP:
a_ship.moving_up = False
if event.key == pygame.K_DOWN:
a_ship.moving_down = False

def update_screen(ai_settings, ai_screen, a_ship, aliens_g, bullets):
"""Update image on the screen and flip to the new screen."""
#Redraw the screen during each pass through the loop
ai_screen.fill(ai_settings.bg_color)
#REDRAW all bullets behind ship and aliens
for bullet in bullets.sprites():
bullet.draw_bullet()
a_ship.blitme()
aliens_g.draw(ai_screen)
#Make the most recently drawn screen visible
pygame.display.flip()
def update_bullet(bullets):
"""Update positions of bullets and delete old ones."""
#Update bullet positions
bullets.update()
#get rid of the old bullets that go off screen
for bullet in bullets.copy():
if bullet.bullet_rect.bottom <= 0:
bullets.remove(bullet)

def create_fleet(ai_settings, ai_screen, aliens_g):
"""Create a full fleet of aliens"""
alien = Alien(ai_settings, ai_screen)
alien_amount_x = get_number_aliens_x(ai_settings, alien.alien_rect.width)
#Create the first row of aliens
for one in range(alien_amount_x):
create_alien(ai_settings, ai_screen, aliens_g, one)
def get_number_aliens_x(ai_settings, alien_width):
"""Determine the amount of alien that fits in a row"""
#Calulations:
availabe_space_x = ai_settings.screen_width - 2 * alien_width
alien_amount_x = int(availabe_space_x / (2 * alien_width))
return alien_amount_x
def create_alien(ai_settings, ai_screen, aliens_g, one):
"""Create an alien and place it in the row."""
alien = Alien(ai_settings, ai_screen)
alien_width = alien.alien_rect.width
alien.x = alien_width + 2 * alien_width * one
alien.alien_rect.x = alien.x
aliens_g.add(alien)

而且。。。这是我的外星模块：

import pygame
from pygame.sprite import Sprite

class Alien(Sprite):
"""A CLASS that MANAGES a single alienn in the fleet."""
def __init__(self, ai_settings, ai_screen):
"""Initialize the alien and start position"""
super().__init__()
self.ai_settings = ai_settings
self.screen = ai_screen
#Load the alien image and SET RECT attribute
self.alien_image = pygame.image.load('images/alien.bmp')
self.alien_rect = self.alien_image.get_rect()
#Set starting point of alien at the top left corner of screen
#settings the space(top and left) to the width and height of image_rect
self.alien_rect.x = self.alien_rect.width
self.alien_rect.y = self.alien_rect.height
self.x_float = float(self.alien_rect.x)
def blit_a(self):
"""Draw alien at its current location"""
self.screen.blit(self.alien_image, self.alien_rect)

Answer 1

Pygame精灵必须具有self.image和self.rect属性，否则精灵组将无法闪电攻击图像，并引发AttributeError。

如果您查看sprite组的draw方法，您将看到它在包含的sprite上进行迭代，并在spr.rect处对spr.image进行blit。

Answer 2

使用名称self.image代替self.alien_image，使用self.rect代替self.alien_rect

Answer 3

命名约定在pygame.sprites中很重要，因此有另一种方法可以解决此问题你可以使用for循环在屏幕上打印单个外星人的，而不是分组绘制(表面(

for alien in aliens_g.sprites():
alien.blit_a()