编写一个游戏，将一艘飞船放在屏幕左侧，并允许玩家上下移动飞船。在玩家按空格键时，

让飞船发射一颗在屏幕中向右飞行的子弹，并在子弹从屏幕中消失后将其删除。

ship_shooting.py

import pygame
import sys
from leftship import LeftShip
from settings import Settings
from ship_bullet import Bullet


class ShipShooting:
    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('飞船横向射击')
        self.bg_color = (232, 232, 232)
        self.clock = pygame.time.Clock()

        self.leftship = LeftShip(self)
        self.bullets = pygame.sprite.Group()

    def run_game(self):
        while True:
            self._check_events()
            self.leftship.update()
            self.bullets.update()
            self._remove_offscreen_bullets()
            self._update_screen()
            self.clock.tick(60)

    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_UP:
            self.leftship.moving_up = True
        elif event.key == pygame.K_DOWN:
            self.leftship.moving_down = True
        elif event.key == pygame.K_q:
            sys.exit()
        elif event.key == pygame.K_SPACE:
            self._fire_bullet()

    def _check_keyup_events(self, event):
        if event.key == pygame.K_UP:
            self.leftship.moving_up = False
        elif event.key == pygame.K_DOWN:
            self.leftship.moving_down = False

    def _fire_bullet(self):
        '''创建一颗子弹，并将其加入编组bullets'''
        new_bullet = Bullet(self)
        self.bullets.add(new_bullet)

    def _remove_offscreen_bullets(self):
        for bullet in self.bullets.copy():
            if bullet.rect.left >= self.settings.screen_width:
                self.bullets.remove(bullet)

    def _update_screen(self):
        '''更新屏幕上的图像，并切换到新屏幕'''
        self.screen.fill(self.settings.bg_color)
        for bullet in self.bullets.sprites():
            bullet.draw_bullet()
        self.leftship.blitme()
        pygame.display.flip()


if __name__ == '__main__':
    # 创建游戏实例并运行游戏
    ss = ShipShooting()
    ss.run_game()

left_ship.py

import pygame


class LeftShip:
    def __init__(self, shooting_game):
        self.screen = shooting_game.screen
        self.settings = shooting_game.settings

        self.screen_rect = shooting_game.screen.get_rect()

        self.image = pygame.image.load('images/ship_left.bmp')
        self.rect = self.image.get_rect()

        self.rect.midleft = self.screen_rect.midleft

        self.y = float(self.rect.y)
        self.moving_up = False
        self.moving_down = False

    def update(self):
        if self.moving_up and self.rect.top >= 0:
            self.y -= self.settings.ship_speed
        elif self.moving_down and self.rect.bottom <= self.screen_rect.bottom:
            self.y += self.settings.ship_speed

        self.rect.y = self.y

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

ship_bullet.py

import pygame
from pygame.sprite import Sprite


class Bullet(Sprite):
    def __init__(self, shooting_game):
        '''在飞船当前位置创建一个子弹'''
        super().__init__()
        self.screen = shooting_game.screen
        self.settings = shooting_game.settings
        # self.color = shooting_game.color

        # 先在（0，0）处创建一个表示子弹的矩形，在设置其位置
        self.rect = pygame.Rect(0, 0, self.settings.bullet_width, self.settings.bullet_height)
        self.rect.midright = shooting_game.leftship.rect.midright

        self.x = float(self.rect.x)

    def update(self):
        '''更新子弹的位置，向右移动'''
        self.x += self.settings.bullet_speed
        self.rect.x = self.x

    def draw_bullet(self):
        '''在屏幕上绘制子弹'''
        pygame.draw.rect(self.screen, self.settings.bullet_color, self.rect)  # rect(画在哪儿，线的颜色，矩形范围，线宽=0)

settings.py

import pygame


class Settings():
    def __init__(self):
        self.screen_width = 600
        self.screen_height = 800
        self.bg_color = (232, 232, 232)

        self.ship_speed = 1

        self.bullet_speed = 2
        self.bullet_width = 15
        self.bullet_height = 3
        self.bullet_color = (60, 60, 60)

运行后：