Is there a unique method in python to unique a list?

[John H. Li]

Thanks first, I could understand the second approach easily. The first
approach is  a bit puzzling. Why are  seen=set() and seen.add(x)  still
necessary there if we can use unique.append(x) alone? Thanks for your
enlightenment.

On Sun, Sep 9, 2012 at 1:59 PM, Donald Stufft <donald.stufft at gmail.com>wrote:

>  seen = set()
> uniqued = []
> for x in original:
>     if not x in seen:
>         seen.add(x)
>         uniqued.append(x)
>
> or
>
> uniqued = []
> for x in oriignal:
>     if not x in uniqued:
>         uniqued.append(x)
>
> The difference between is option #1 is more efficient speed wise, but uses
> more memory (extraneous set hanging around), whereas the second is slower
> (``in`` is slower in lists than in sets) but uses less memory.
>
> On Sunday, September 9, 2012 at 1:56 AM, John H. Li wrote:
>
> Many thanks. If I want keep the order, how can I deal with it?
> or we can list(set([1, 1, 2, 3, 4])) = [1,2,3,4]
>
>
> On Sun, Sep 9, 2012 at 1:47 PM, Donald Stufft <donald.stufft at gmail.com>wrote:
>
>  If you don't need to retain order you can just use a set,
>
> set([1, 1, 2, 3, 4]) = set([1, 2, 3, 4])
>
> But set's don't retain order.
>
> On Sunday, September 9, 2012 at 1:43 AM, Token Type wrote:
>
> Is there a unique method in python to unique a list? thanks
> --
> http://mail.python.org/mailman/listinfo/python-list
>
>
>
>
>
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