Python编程——火箭：编写一个游戏，开始时屏幕中央有一个火箭，而玩家可使用四个方向键上下左右移动火箭。请务必确保火箭不会移到屏幕外面。

import pygame

class RocketSettings:
    def __init__(self):
        self.dis_width = 1000
        self.dis_height = 600
        self.dis_color = (255, 255, 255)

        self.moving_speed = 1.5

import pygame

class RocketImages:
  def __init__(self, rocket_pos):
      self.screen = rocket_pos.screen
      self.settings = rocket_pos.settings
      self.screen_rect = rocket_pos.screen.get_rect()

      self.image = pygame.image.load("images/rocket.bmp")
      self.rect = self.image.get_rect()

      self.rect.midbottom = self.screen_rect.midbottom

      self.moving_right = False
      self.moving_left = False
      self.moving_up = False
      self.moving_down = False
      self.x = float(self.rect.x)
      self.y = float(self.rect.y)

  def pos_update(self):
      if self.moving_right and self.rect.right < self.screen_rect.right:
          self.x += self.settings.moving_speed
      if self.moving_left and self.rect.left > 0:
          self.x -= self.settings.moving_speed
      if self.moving_up and self.rect.top > 0:
          self.y -= self.settings.moving_speed
      if self.moving_down and self.rect.bottom < self.screen_rect.bottom:
          self.y += self.settings.moving_speed

      self.rect.x = self.x   
      self.rect.y = self.y

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

import sys
import pygame
from Rocket_setting import RocketSettings
from Rocket_images import RocketImages

class RocketMain:
   def __init__(self):
       pygame.init()

       self.settings = RocketSettings()

       self.screen = pygame.display.set_mode((self.settings.dis_width, self.settings.dis_height))
       pygame.display.set_caption("RocketGame")

       self.rocket_image = RocketImages(self)

   def rocket_run(self):
       while True:
           self._check_events()
           self.rocket_image.pos_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 _update_screen(self):
       self.screen.fill(self.settings.dis_color)
       self.rocket_image.blitrocket()
       pygame.display.flip()

   def _check_keydown_events(self, event):
       if event.key == pygame.K_RIGHT:
           self.rocket_image.moving_right = True
       elif event.key == pygame.K_LEFT:
           self.rocket_image.moving_left = True
       elif event.key == pygame.K_UP:
           self.rocket_image.moving_up = True
       elif event.key == pygame.K_DOWN:
           self.rocket_image.moving_down = True
       elif event.key == pygame.K_q:
           sys.exit()

   def _check_keyup_events(self, event):
       if event.key == pygame.K_RIGHT:
           self.rocket_image.moving_right = False
       if event.key == pygame.K_LEFT:
           self.rocket_image.moving_left = False
       if event.key == pygame.K_UP:
           self.rocket_image.moving_up = False
       if event.key == pygame.K_DOWN:
           self.rocket_image.moving_down = False

if __name__ == '__main__':
   rocket = RocketMain()
   rocket.rocket_run()

### 2.1 演示效果