Python外星人入侵项目AttributeError: 无_check_events属性报错修复

运行invasion.py时抛出如下错误：

AttributeError: 'AlienInvasion' object has no attribute '_check_events'

核心问题是Python类方法缩进错误：

• _check_events方法被错误嵌套定义在run_game方法内部，不属于AlienInvasion类的直接实例方法，实例调用self._check_events()时自然找不到对应属性。
• _check_keydown_events、_check_keyup_events被进一步嵌套在_check_events方法内部，同样无法被类实例正常访问。
• 代码还存在一个隐藏bug：Ship类的update方法调用了self.settings.ship_speed，但Ship初始化时未保存传入的settings实例，飞船移动逻辑触发时会抛出新的属性错误。

1. 调整invasion.py内所有类方法的缩进，把嵌套在其他方法内部的方法全部移动到AlienInvasion类的直接层级，和__init__、run_game方法保持同级缩进。
2. 修改Ship.py的初始化方法，将传入的游戏实例中的settings对象保存为Ship实例的自身属性，修复移动逻辑的参数调用问题。
3. settings.py代码逻辑正确，无需修改。

修复后完整代码 #

invasion.py #

import sys
import pygame

from settings import Settings
from ship import Ship

class AlienInvasion:
    def __init__(self):
        pygame.init()
        self.settings = Settings()
        self.screen = pygame.display.set_mode(
            (self.settings.screen_width, self.settings.screen_height))
        pygame.display.set_caption("Aliens is invading!")
        self.ship = Ship(self)
        self.bg_color = (230, 230, 230)

    def run_game(self):
        while True:
            self._check_events()
            self.ship.update()
            self._update_screen()

    def _check_events(self):
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                sys.exit()
            elif event.type == pygame.KEYDOWN:
                self._check_keydown_events(event)
            elif event.type == pygame.KEYUP:
                self._check_keyup_events(event)

    def _check_keydown_events(self, event):
        if event.key == pygame.K_RIGHT:
            self.ship.moving_right = True
        elif event.key == pygame.K_LEFT:
            self.ship.moving_left = True

    def _check_keyup_events(self, event):
        if event.key == pygame.K_RIGHT:
            self.ship.moving_right = False
        elif event.key == pygame.K_LEFT:
            self.ship.moving_left = False

    def _update_screen(self):
        self.screen.fill(self.settings.bg_color)
        self.ship.blitme()
        pygame.display.flip()


if __name__ == '__main__':
    ai = AlienInvasion()
    ai.run_game()

Ship.py #

import pygame

class Ship:
    def __init__(self, ai_game):
        self.screen = ai_game.screen
        self.screen_rect = ai_game.screen.get_rect()
        # 绑定settings属性，解决移动速度参数调用报错
        self.settings = ai_game.settings

        self.image = pygame.image.load('images/shipdos.bmp')
        self.rect = self.image.get_rect()
        self.rect.midbottom = self.screen_rect.midbottom

        self.x = float(self.rect.x)
        self.moving_right = False
        self.moving_left = False

    def update(self):
        if self.moving_right and self.rect.right < self.screen_rect.right:
            self.x += self.settings.ship_speed
        if self.moving_left and self.rect.left > 0:
            self.x -= self.settings.ship_speed
        self.rect.x = self.x

    def blitme(self):
        self.screen.blit(self.image, self.rect)

内容的提问来源于stack exchange，提问作者Leo X