Change initial element of a list keeping the sequence

Question

I have an algorithm that outputs a list in a specific order, for example:

[0 4 3 2 1 5]

I want to reorder the list to start with the element '1' and keep the sequence, so my output would be:

[1 5 0 4 3 2]

I've searched and tried different possibilities but I'm still struggling with it.

How can I make this work?

Then it is no longer a simple comment-worty one-liner if I don't call it twice (named assignments notwithstanding) =) — user2390182, Jan 25 '21 at 15:10

score 3 · Accepted Answer · answered Jan 25 '21 at 15:12

3

lst = [0, 4, 3, 2, 1, 5]

to rotate it into position:

i = lst.index(1)
lst = lst[i:] + lst[:i]

answered Jan 25 '21 at 15:12

user2390182

Can make one-liner with Walrus operator: `lst = lst[(p:=lst.index(1)):] + lst[:p]` – DarrylG Jan 25 '21 at 15:19
I am well aware, as seen in my comments. However, it only works in the most recent Python versions and does not make it more readable or performant. – user2390182 Jan 25 '21 at 15:23

1 Answers1