How to get rid of repetitive elements in a Python list?

Question

Possible Duplicate:
How do you remove duplicates from a list in Python whilst preserving order?

I have list of integers in Python. Some of the values are present several times in the list. What is an elegant way to get list out of first list, where each element is presented once?

@RikPoggi your link is not pointing a duplicate of this question :-) — Simon Bergot, Feb 07 '12 at 17:38
This isn't quite a duplicate of the above, because the above concerns order. Here's a true duplicate: http://stackoverflow.com/q/8200342/ — senderle, Feb 07 '12 at 17:59

score 3 · Answer 1 · edited Feb 07 '12 at 17:50

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One nice way that isn't guaranteed to maintain the ordering:

l = list(set(l))

edited Feb 07 '12 at 17:50

Rik Poggi

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answered Feb 07 '12 at 17:33

Guy Adini

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score 1 · Answer 2 · answered Feb 07 '12 at 17:34

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list(set(your_list))

But if you don't want duplicates, maybe you should be using a set instead of a list in the first place?

answered Feb 07 '12 at 17:34

Matti Virkkunen

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score 0 · Answer 3 · edited Feb 07 '12 at 17:39

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Using set:

dup_list = (1,2,2,3,3,3)
cleaned_list = list(set(dup_list))

edited Feb 07 '12 at 17:39

Peter Mortensen

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answered Feb 07 '12 at 17:36

istruble

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score 0 · Answer 4 · answered Feb 07 '12 at 17:36

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Use itertools.groupby ( http://docs.python.org/library/itertools.html#itertools.groupby ).

From the docs: [k for k, g in groupby('AAAABBBCCDAABBB')] --> A B C D A B

You will likely wish to use sorted also.

answered Feb 07 '12 at 17:36

Marcin

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How to get rid of repetitive elements in a Python list?

4 Answers4