How to convert a list of lists of lists into a list of lists?

Question

I have

testlist = [[["a", "b", "c"]], [["a", "b", "c"], ["a", "b", "c"]]]

and want

finalist = [["a", "b", "c"], ["a", "b", "c"], ["a", "b", "c"]]

I've tried

finalist = [[item for subsublist in sublist for item in subsublist] for sublist in testlist]

but this gives me

finalist = [["a", "b", "c"], ["a", "b", "c", "a", "b", "c"]]

This is a common question and there's already a ton of detailed answers in this post: https://stackoverflow.com/questions/952914/how-to-make-a-flat-list-out-of-a-list-of-lists I tested `list(itertools.chain(*testlist))` on your data and it does just what you want. — gavinb, Apr 20 '21 at 03:20

score 3 · Accepted Answer · answered Apr 20 '21 at 03:13

3

I tried this on your input. I think you just have to worry about the sublists and unpack them. Your approach is flattening sublists first which is why that last portion was wrong

[l for s in testlist for l in s]

answered Apr 20 '21 at 03:13

Buckeye14Guy

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How to convert a list of lists of lists into a list of lists?

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