如何从嵌套列表中删除小于给定长度的条目

def remove_short_items(nested_list, length):
    if isinstance(nested_list, list):
        for item in nested_list:
            remove_short_items(item, length)
        nested_list[:] = [item for item in nested_list if len(str(item)) >= length]

nested_list = [1, [2, 3, [4, 5], 6], [7, 8, [9, 10, 11]], 12]
length = 2

remove_short_items(nested_list, length)
print(nested_list)

[[2, 3, [4, 5], 6], [7, 8, [9, 10, 11]]]