save project

snake.py

@@ -59,8 +59,10 @@ while True:
         num2= random.randint(1,16)
         apple_x=num1*30-30
         apple_y=num2*30-30
+        score+=10
     else:
         position.pop(0)
+        if x < 0 or x >630 or y  <0 or y > 450:
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去