class - isinstance 在我的类 python 的 __init__ 中被卡住（或无限循环？）

Question

所以我有一个类 Panini，我必须对其进行初始化，但它一直卡在 assert isinstance(stickers, (int, tuple, set, list)), 'invalid stickers' 行中，当我删除该行时它卡住了在下一个例子中，有人可以告诉我我在这里做错了什么吗？

class Panini:
    def __init__(self, stickers):
            self.stickers = stickers
            #test if stickers is integer or a list/tuple/set of integers
            assert isinstance(stickers, (int, tuple, set, list)), 'invalid stickers'
            if isinstance(stickers, (set, tuple, list)):
                try: int_list = [int(x) for x in stickers]
                except ValueError:
                    raise 'invalid sticker'

            #if list or tuple contains duplicate integers(stickers) then these must be included in the collection only once
            if isinstance(stickers, (list, tuple)):
                my_set = set(stickers)
                if isinstance(stickers, tuple): stickers = tuple(my_set)
                else: stickers = list(my_set)