Reorder list in Python

Question

I would like to reorder a python list:

a = [1,2,3,4,5,6,7,...]

to the following form:

[[1,2,3],[2,3,4],[3,4,5],...]

What is the fastest way to do that?

http://stackoverflow.com/questions/6614891/turning-a-list-into-nested-lists-in-python — Harsha Biyani, Dec 13 '16 at 13:05
What happens at the end of your source list? Do you just get a two-element list and a one-element list in your result? — Ulrich Schwarz, Dec 13 '16 at 13:07
Really easy to do in one line : a = [1,2,3,4,5] and then b = [[a[i], a[i+1], a[i+2]] for i in range (0, len(a) -2)] — iFlo, Dec 13 '16 at 13:10
`b = [a[i:i+3] for i in range(len(a))]` Does depend on Ulrich Schwarz's question though. — elParaguayo, Dec 13 '16 at 13:12
This is not a duplicate. Initial question want to produce [(1,2,3),(4,5,6),(7,8,9)]. This question want to produce [(1,2,3),(2,3,4),(3,4,5),...,(6,7,8),(7,8,9)]. — Setop, Dec 13 '16 at 13:22

score 1 · Answer 1 · answered Dec 13 '16 at 13:10

1

you can try:

>>> a = [1,2,3,4,5,6,7]
>>> new_list = []
>>> for index in range(len(a)-2):
    new_list.append(a[index:index+3])


>>> new_list
[[1, 2, 3], [2, 3, 4], [3, 4, 5], [4, 5, 6], [5, 6, 7]]

answered Dec 13 '16 at 13:10

Harsha Biyani

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or try zip(a, a[1:], a[2:]) – Setop Dec 13 '16 at 13:25

Reorder list in Python

1 Answers1