import sys
import pygame

from contants import BG_MUSIC, BG_IMG, IMG_GAME_TITLE


def main():
   """游戏入口，main方法"""
   #初始化
   pygame.init()

   width,height =480,852
   #屏幕对象
   screen = pygame.display.set_mode((width,height))
   #设置窗口标题
   pygame.display.set_caption("飞机大战")
   #加载背景图片
   bg = pygame.image.load(BG_IMG)
   #游戏的标题
   img_game_title = pygame.image.load(IMG_GAME_TITLE)
   #加载背景音乐
   pygame.mixer.music.load(BG_MUSIC)
   pygame.mixer.music.play(-1)#无限循环播放
   pygame.mixer.music.set_volume(0.2)#设置音量大小

   status = 0 #0准备中，1游戏中，2游戏结束

   while True:
       #1 监听事件
       for event in pygame.event.get():
           #退出游戏
           if event.type == pygame.QUIT:
               pygame.quit()
               sys.exit()
       #更新游戏的状态
       if status == 0:
           #游戏准备中
           screen.blit()

       #绘制
       screen.blit(bg,bg.get_rect())
       pygame.display.flip()

if __name__ == '__main__':
   main()

报错：

D:\untitled\venv\Scripts\python.exe D:/untitled1/cheapter12/main.py

pygame 1.9.6

Hello from the pygame community. https://www.pygame.org/contribute.html

Traceback (most recent call last):

  File "D:/untitled1/cheapter12/main.py", line 45, in <module>

    main()

  File "D:/untitled1/cheapter12/main.py", line 38, in main

    screen.blit()

TypeError: function missing required argument 'source' (pos 1)

Process finished with exit code 1