如何在python的嵌套列表中找到列表的索引

Question

I've got a list which I want to find the index of a nested list using one of the tuples (16, 29, 32, 40) like a dictionary.

list2 = [[(4, 8, 16, 29), 1, '[#1]:'], [(16, 29, 32, 40), 1, '[#2]:']]
item_position = list2.index([(16, 29, 32, 40)]) #Error here!
print("item_position", item_position)

Output error:
 item_position = list2.index([(16, 29, 32, 40)])
ValueError: [(16, 29, 32, 40)] is not in list

When the list is:

list2 = [[(4, 8, 16, 29), 1, '[#1]:'], [(16, 29, 32, 40)]]

the value is:

item_position 1

so I know it can work. Just wondering if someone can show me the correct code. Thanks in advance.

Answer 1

One way would be to iterate over your list, remembering each item that matches:

In [3]: item_position = [i for i, x in enumerate(list2) if x[0] == (16,29,32,40) ]

In [4]: print("item_position", item_position)
item_position [1]