list comprehension even list elements instead of loop and how to refer only to the index

Question

I want to use list comp' instead of a loop. Let's sat I have a list of lists and I want only the even index elements. Eg: [[a,a], [b,b], [c,c],[g,g]] to..... [[a,a], [c,c]]

This doesn't work


a = [i for i in the_list if i % 2 == 0)]

You have to iterate over the index, not the element in itself, use `enumerate`. Or just take a slice `l[::2]` — yatu, Dec 05 '19 at 10:27

Riccardo Bucco · Answer 1 · 2019-12-05T10:30:06.427

1

Here is a possible solution that keeps only lists with even indexes:

result = [lst for i, lst in enumerate(the_list) if i % 2 == 0]

edited Dec 05 '19 at 10:30

answered Dec 05 '19 at 10:28

Riccardo Bucco

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Oh great. Thought I missed the index number. Thank you! – tibetish Dec 05 '19 at 10:30

list comprehension even list elements instead of loop and how to refer only to the index

1 Answers1