Need some help with "Replace First"

Have no idea what is wrong. In cmd it work:

    def replace_first(items: list) -> Iterable:
    try: 
            items = items.append(items[0])    
            items_a = items[1:]
            return items_a
    except ValueError:
            return items
Result:
TypeError: 'NoneType' object is not subscriptable
 replace_first, 8
 <module>, 15