Python速成班外星人入侵| AttributeError:“Bullet”对象没有属性“speed_factor”

Question

我正在做Python外星人入侵速成班，当我测试这段代码时，突然出现一个错误，说“Bullet”没有对象“speed_factor”

我一直在寻找原因，多次检查代码，甚至将其与其他代码进行比较，但一切似乎都很好

游戏代码（alien_invision.py）：

import sys
import game_functions as gf
import pygame
from settings import Settings
from ship import Ship
from pygame.sprite import Group

def run_game():
# Initialize pygame, settings, and screen object.
 pygame.init()
 ai_settings = Settings()



screen = pygame.display.set_mode((ai_settings.screen_width, ai_settings.screen_height))
pygame.display.set_caption("Alien Invasion")

screen.fill(ai_settings.bg_color)
# Make a ship.
ship = Ship(screen, ai_settings)
bullets = Group()

# Background color
bg_color = (230, 230, 230)


while True:

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

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


    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

    screen.fill(ai_settings.bg_color)

    ship.blitme()
    pygame.display.flip()

run_game()

设置代码（Settings.py）：

class Settings():
def __init__(self):
    self.screen_width = 1200
    self.screen_height = 800
    self.bg_color = (230, 230, 230)
    self.ship_speed_factor = 2

    self.bullet_speed_factor = 1
    self.bullet_width = 3
    self.bullet_height = 12
    self.bullet_color = (60, 60, 60)
    self.bullet_limit = 5

船舶代码（Ship.py）：

import pygame
from pygame.sprite import Sprite

class Ship(Sprite):
def __init__(self, screen, ai_settings):
    self.screen = screen
    self.ai_settings = ai_settings
    self.image = pygame.image.load(r'C:\Users\user\Desktop\alien invasion\ship.bmp')
    self.rect = self.image.get_rect()
    self.screen_rect = screen.get_rect()
    self.rect.centerx = self.screen_rect.centerx
    self.rect.bottom = self.screen_rect.bottom
    self.moving_right = False
    self.moving_left = False
    self.center = float(self.rect.centerx)
    self.center += self.ai_settings.ship_speed_factor



def update(self, ai_settings):
    self.ai_settings = ai_settings
    if self.moving_right and self.rect.right < self.screen_rect.right:
        self.rect.centerx += 1
        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
        self.rect.centerx -= 1


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

项目符号代码（Bullet.py）：

import pygame
from pygame.sprite import Sprite

class Bullet(Sprite):

def __init__(self, ai_settings, screen, ship):
    super().__init__()
    self.screen = screen
    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
    self.y = float(self.rect.y)
    self.color = ai_settings.bullet_color
    self.ship_speed_factor = ai_settings.bullet_speed_factor

def update(self):
    self.y -= self.speed_factor
    self.rect.y = self.y


def draw_bullet(self):
    pygame.draw.rect(self.screen, self.color, self.rect)

game_functions.py：

import pygame
from bullet import Bullet

def check_keydown_events(event, ship, ai_settings, screen, bullets):
    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:
        new_bullet =  Bullet(ai_settings, screen, ship)
        bullets.add(new_bullet)

def check_keyup_events(event, ship):
    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):

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event,ship, ai_settings, screen, bullets)
            if event.key == pygame.K_RIGHT:
                ship.moving_right = True

            elif event.key == pygame.K_LEFT:
                ship.moving_left = True

        elif event.type == pygame.KEYUP:
           if event.key == pygame.K_RIGHT:
             ship.moving_right = False

           elif event.key == pygame.K_LEFT:
             ship.moving_left = False

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

    for bullet in bullets.sprites():
        bullet.draw_bullet()
        ship.blitme()

错误日志：

File "C:\Users\user\Desktop\alien invasion\bullet.py", line 17, in update
self.y -= self.speed_factor
AttributeError: 'Bullet' object has no attribute 'speed_factor'

我真的很感激任何帮助，因为这让我发疯

Answer 1

在Bullet类的__init__中，您正在设置self.ship_speed_factor，但在其update方法中，您正在尝试执行self.y -= self.speed_factor。
我猜您只是使用了一个错误的字段名，在这种情况下，您应该执行以下任一操作：

• 用update中的self.y -= self.ship_speed_factor替换self.y -= self.speed_factor
• 在__init__中用self.speed_factor = ...替换self.ship_speed_factor = ...