save project

snake.py

@@ -56,8 +56,9 @@ while True:
     if (x,y) == (apple_x,apple_y):
         apple_x = random.randint(0,21)*30
         apple_y = random.randint(0,15)*30
-    position.append((x, y))
+    else:
         position.pop(0)
+    position.append((x, y))
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去