CODEWITHSUNDEEP
pythonpython-3.x
silmil
silmil

Reputation: 29

Group numbers in a list by their indices (python0

I have this group of numbers:

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

and I have their indices grouped like this:

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

I want to group the numbers in list 'a' in the way how their indices are grouped to get something like this:

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

Thanks for your help!

Upvotes: 2

Views: 53

Answers (2)

Mykola Zotko
Mykola Zotko

Reputation: 17911

You can use the function itemgetter():

from operator import itemgetter

a = [1,2,3,4,5,6]
indices = [[0],[1,2],[3,4,5]]

[list(itemgetter(*i)(a)) if len(i) > 1 else [itemgetter(*i)(a)]
                                              for i in indices]
#  [[1], [2, 3], [4, 5, 6]]

Upvotes: 0

Andrew McDowell
Andrew McDowell

Reputation: 2980

This should do the trick:

a = [1,2,3,4,5,6]
indices = [[0],[1,2],[3,4,5]]

result = [[a[index] for index in index_list] for index_list in indices]

Upvotes: 4

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