auto save

snake.py

@@ -64,8 +64,12 @@ while True:
     for i in range(len(position)-1):
         screen.blit(body, position[i])
     if apple_x and apple_y==x and y:
-        apple_x=random.randint(0,660)
-        apple_y=random.randint(0,480)
+        apple_x=random.randint(0,21)
+        apple_y=random.randint(0,15)
+        apple_x=30*num1
+        apple_y=30*num2
+    else
+        position.pop(0) 
     # 将果实画上去
     screen.blit(food, (apple_x,apple_y))
     # 刷新画面