save project

snake.py

@@ -53,9 +53,11 @@ while True:
     else:
         y += 30
     position.append((x, y))
-    if x == apple_X and y == apple_y
+    if x == apple_X and y == apple_y:
         apple_X = random.randint(0,660)
         apple_y = random.randint(0,480)
+    else:
+        position.pop(0)
     position.pop(0)
     # 将背景图画上去
     screen.blit(background, (0, 0))