[Tutor] permutations?

[Alex Hall]

Thanks to everyone for the itertools hint; that sounds like it will work.

Sorry I was not clearer:
1. Order matters; I meant to say that direction does not. That is, 123
is not the same as 213, but 123 is the same as 321 since the second
example is simply a reversal.
2. I am looking for all permutations and subpermutations (if that is a
word) of 1-n where the list must have at least 2, but no more than n,
unique numbers (so 1 is not valid, nor is 1231 since it repeats 1 and
is too long for n=3).
I hope that makes sense. However, hopefully itertools will do it; if I
run into problems I will respond to this email to keep it in the same
thread. Thanks again! Oh, to the person who asked, I have 2.6 and 2.7
installed, with the default being 2.6.

On 12/1/10, bob gailer <bgailer at gmail.com> wrote:
> On 12/1/2010 5:45 PM, Alex Hall wrote:
>> Hi all,
>> I am wondering if there is a python package that will find
>> permutations? For example, if I have (1, 2, 3), the possibilities I
>> want are:
>> 12
>> 13
>> 23
>> 123
>> 132
>> 231
>>
>> Order does not matter; 21 is the same as 12, but no numbers can
>> repeat. If no package exists, does someone have a hint as to how to
>> get a function to do this? The one I have right now will not find 132
>> or 231, nor will it find 13. TIA.
>
> According to Wikipedia " there are six permutations of the set {1,2,3},
> namely [1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], and [3,2,1]."
>
> Above you show some "combinations" and a subset of the permutations.
>
> What rules did you apply to come up with your result?
>
> --
> Bob Gailer
> 919-636-4239
> Chapel Hill NC
>
>


-- 
Have a great day,
Alex (msg sent from GMail website)
mehgcap at gmail.com; http://www.facebook.com/mehgcap