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Re: Most pythonic way of rotating a circular list to a canonical point

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On 8/1/2015 1:34 PM, Lukas Barth wrote:
> Hi!
>
> I have a list of numbers that I treat as "circular", i.e. [1,2,3] and [2,3,1] should be the same. Now I want to rotate these to a well defined status, so that I can can compare them.
>
> If all elements are unique, the solution is easy: find the minimum element, find its index, then use mylist[:index] + mylist[index:], i.e. the minimum element will always be at the beginning.
>
> But say I have [0,1,0,2,0,3]. I can in fact guarantee that no *pair* will appear twice in that list, i.e. I could search for the minimum, if that is unique go on as above, otherwise find *all* positions of the minimum, see which is followed by the smallest element, and then rotate that position to the front.
>
> Now that seems an awful lot of code for a (seemingly?) simple problem. Is there a nice, pythonic way to do this?

Well, I have not understood the problem for such a seemingly simple one.  :)

Is the problem to determine if one list of circular numbers 'matches' 
another one despite rotation status?  If so, I'd do something like:

def matchcircularlists(L1,L2):
     #return True if L1 is a rotation variant of L2
     return "".join(map(str,L1)) in "".join(map(str,L2+L2))

Emile

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Most pythonic way of rotating a circular list to a canonical point Lukas Barth <mail@tinloaf.de> - 2015-08-01 13:34 -0700
  Re: Most pythonic way of rotating a circular list to a canonical point Emile van Sebille <emile@fenx.com> - 2015-08-01 13:49 -0700
    Re: Most pythonic way of rotating a circular list to a canonical point Lukas Barth <mail@tinloaf.de> - 2015-08-01 14:12 -0700
      Re: Most pythonic way of rotating a circular list to a canonical point Emile van Sebille <emile@fenx.com> - 2015-08-01 14:29 -0700
  Re: Most pythonic way of rotating a circular list to a canonical point Marko Rauhamaa <marko@pacujo.net> - 2015-08-01 23:57 +0300
    Re: Most pythonic way of rotating a circular list to a canonical point Lukas Barth <mail@tinloaf.de> - 2015-08-01 14:04 -0700
      Re: Most pythonic way of rotating a circular list to a canonical point Lukas Barth <mail@tinloaf.de> - 2015-08-01 16:32 -0700
      Re: Most pythonic way of rotating a circular list to a canonical point Marko Rauhamaa <marko@pacujo.net> - 2015-08-02 09:25 +0300
  Re: Most pythonic way of rotating a circular list to a canonical point Lukas Barth <mail@tinloaf.de> - 2015-08-01 14:24 -0700
    Re: Most pythonic way of rotating a circular list to a canonical point Emile van Sebille <emile@fenx.com> - 2015-08-01 14:36 -0700
      Re: Most pythonic way of rotating a circular list to a canonical point Lukas Barth <mail@tinloaf.de> - 2015-08-01 15:51 -0700
        Re: Most pythonic way of rotating a circular list to a canonical point Joel Goldstick <joel.goldstick@gmail.com> - 2015-08-01 18:58 -0400
        Re: Most pythonic way of rotating a circular list to a canonical point Josh English <Joshua.R.English@gmail.com> - 2015-08-01 16:43 -0700
        Re: Most pythonic way of rotating a circular list to a canonical point Steven D'Aprano <steve@pearwood.info> - 2015-08-02 18:17 +1000
    Re: Most pythonic way of rotating a circular list to a canonical point Paul Rubin <no.email@nospam.invalid> - 2015-08-01 14:43 -0700
      Re: Most pythonic way of rotating a circular list to a canonical point Lukas Barth <mail@tinloaf.de> - 2015-08-01 15:53 -0700
        Re: Most pythonic way of rotating a circular list to a canonical point Paul Rubin <no.email@nospam.invalid> - 2015-08-01 19:47 -0700
          Re: Most pythonic way of rotating a circular list to a canonical point Paul Rubin <no.email@nospam.invalid> - 2015-08-01 20:02 -0700
    Re: Most pythonic way of rotating a circular list to a canonical point Cameron Simpson <cs@zip.com.au> - 2015-08-02 08:25 +1000
      Re: Most pythonic way of rotating a circular list to a canonical point Lukas Barth <mail@tinloaf.de> - 2015-08-01 15:55 -0700
        Re: Most pythonic way of rotating a circular list to a canonical point Cameron Simpson <cs@zip.com.au> - 2015-08-02 11:20 +1000
  Re: Most pythonic way of rotating a circular list to a canonical point wolfram.hinderer@googlemail.com - 2015-08-01 17:07 -0700
  Re: Most pythonic way of rotating a circular list to a canonical point pavlovevidence@gmail.com - 2015-08-02 03:51 -0700
  Re: Most pythonic way of rotating a circular list to a canonical point Tim Chase <python.list@tim.thechases.com> - 2015-08-02 13:19 -0500
  Re: Most pythonic way of rotating a circular list to a canonical point Larry Hudson <orgnut@yahoo.com> - 2015-08-02 13:01 -0700
    Re: Most pythonic way of rotating a circular list to a canonical point Joonas Liik <liik.joonas@gmail.com> - 2015-08-02 23:58 +0300
      Re: Most pythonic way of rotating a circular list to a canonical point Larry Hudson <orgnut@yahoo.com> - 2015-08-03 12:56 -0700
    Re: Most pythonic way of rotating a circular list to a canonical point Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-08-03 15:19 +0100

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