save project

snake.py

@@ -54,7 +54,7 @@ while True:
     else:
         y += 30
     position.append((x, y))
-    position.pop(0)
+    
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去
@@ -68,6 +68,8 @@ while True:
     if a_x==x and a_y==y:
         a_x=30*random.randint(0,21)
         a_y=30*random.randint(0,15)
+    else:
+        position.pop(0)
 
     # 刷新画面
     pygame.display.update()