我目前正在尝试添加过滤器到菜单API，但它似乎不工作
这是我在www.example.com中尝试的views.py:

@api_view()
def menu_items(request):
    if request.method == "GET":
        items = MenuItem.objects.select_related('category').all()
        category_name = request.query_params.get('category')
        to_price = request.query_params.get('to_price')
        search = request.query_params.get('search')
        if category_name:
            items = items.filter(category__title=category_name)
        if to_price is not None:
            items = items.filter(price__lte=to_price) # lte means price is less then or equal to the value to_price
        if search:.
            items = items.filter(title__icontains=search) # If the characters are present anywhere in the title. This is case insensitive.
        serialized_item = MenuItemSerializer(items, many=True)
        return Response(serialized_item.data)
    if request.method == 'POST':
        serialized_item = MenuItemSerializer(data=request.data)
        serialized_item.is_valid(raise_exception=True)
        serialized_item.save() # Saves the validated data to the database
        return Response(serialized_item.data, status.HTTP_201_CREATED)

每当我转到设置了过滤器值的端点时，我都会得到一个空列表，而不是过滤后的菜单项列表：
empty list when filtered
这是没有过滤的情况：
menu items list unfiltered
我做错什么了吗？我正在遵循一个教程，它对教程有效，但对我的无效。