将值添加/附加到列表中的特定索引

Question

I have the following list:

a = [['628', 'facial-expressions_2868588k.jpg', 'anger', '2'], ['628', 'facial-expressions_2868585k.jpg', 'surprise', '5'], ['628', 'facial-expressions_2868584k.jpg', 'disgust', '6'], ['628', 'facial-expressions_2868582k.jpg', 'fear', '4'], ['dwdii', 'Aaron_Eckhart_0001.jpg', 'neutral', '3'], ['302', 'Aaron_Guiel_0001.jpg', 'happiness', '1'], ['302', 'Aaron_Patterson_0001.jpg', 'neutral', '3'], ['302', 'Aaron_Peirsol_0001.jpg', 'happiness', '1'], ['302', 'Aaron_Peirsol_0002.jpg', 'happiness', '1'], ['302', 'Aaron_Peirsol_0003.jpg', 'happiness', '1'], ['302', 'Aaron_Peirsol_0004.jpg', 'neutral', '3'], ['302', 'Aaron_Pena_0001.jpg', 'neutral', '3']]

I want to append/add values to the indexes of this list. Let's say I want to append 'hi' to the first index of this list to get the following:

a = [['628', 'facial-expressions_2868588k.jpg', 'anger', '2', 'hi'], ['628', 'facial-expressions_2868585k.jpg', 'surprise', '5'], ['628', 'facial-expressions_2868584k.jpg', 'disgust', '6'], ['628', 'facial-expressions_2868582k.jpg', 'fear', '4'], ['dwdii', 'Aaron_Eckhart_0001.jpg', 'neutral', '3'], ['302', 'Aaron_Guiel_0001.jpg', 'happiness', '1'], ['302', 'Aaron_Patterson_0001.jpg', 'neutral', '3'], ['302', 'Aaron_Peirsol_0001.jpg', 'happiness', '1'], ['302', 'Aaron_Peirsol_0002.jpg', 'happiness', '1'], ['302', 'Aaron_Peirsol_0003.jpg', 'happiness', '1'], ['302', 'Aaron_Peirsol_0004.jpg', 'neutral', '3'], ['302', 'Aaron_Pena_0001.jpg', 'neutral', '3']]

How can I do that?

Answer 1

执行a[0].append('hi')因为您想要的列表是列表a的第 0 个索引。

Answer 2

a[0].append('hi') . Just go from the outer index number to the inner one. For example if you have the list below:

num_list = [1, [2, 3], [4, [5], 6]]

Imagine you want to add 0 to have the following:

num_list = [1, [2, 3], [4, [5, 0], 6]]

In order to do so, you need to do this:

num_list[2][1].append(0)