搜索int的嵌套列表

Question

如果在给定的嵌套列表中找到给定的'to_find'，我如何编写一个返回true的递归函数。

例如：

>>> searchNested([1,[4, 5, 6, [2, 10], 9], [1, 4, 5]], 2)
True

Answer 1

def searchNested(xs, y):
    if y == xs:
        return True
    return isinstance(xs, list) and any(searchNested(x, y) for x in xs)

---

>>> searchNested([1,[4, 5, 6, [2, 10], 9], [1, 4, 5]], 2)
True
>>> searchNested([1,[4, 5, 6, [8, 10], 9], [1, 4, 5]], 2)
False

Answer 2

先展平，然后使用in

def searchNested(lst,needle):
    def flatten(target):
        return_list = list()
        for element in target:
            if isinstance(element,list):
                return_list.extend(flatten(element))
            else:
                return_list.append(element)
        return return_list

    lst = flatten(lst)
    if needle in lst: return True
    else: return False