How can I remove unnecessary square brackets Python

Question

For example, I'm having this: a = [['1'], ['2'], ['3']]

How can I change it into: a = ['1', '2', '3']

Thanks!

You have a list of lists, and it appears that you want a list. But the square brackets aren't really unnecessary, because that is how you represent a list of lists. So your question is really "How do I flatten a list of lists into a single list containing the elements of all the sublists?" And as you can see from the comments and answers, there are a lot of ways to do that. — BoarGules, Nov 16 '18 at 10:56

score 1 · Answer 1 · answered Nov 16 '18 at 10:53

1

ooh, i'll play.

a = [i[0] for i in a]

(assuming you only have one item in each sublist)

answered Nov 16 '18 at 10:53

Stael

score 0 · Answer 2 · answered Nov 16 '18 at 10:53

0

Like so:

a = [['1'], ['2'], ['3']]
lst = []
for subLst in a:
    lst.extend(subLst)
print(lst)

But in most cases this means that the generation of the list a get improved ...

answered Nov 16 '18 at 10:53

quant

2 Answers2