Re: a better way to invert a list?

From	scattered <tooscattered@gmail.com>
Newsgroups	comp.lang.python
Subject	Re: a better way to invert a list?
Date	2011-04-06 02:48 -0700
Organization	http://groups.google.com
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On Apr 6, 4:48 am, Glazner <yoavglaz...@gmail.com> wrote:
> > > def invert(p):
> > >     inverse = [None] * len(p)
> > >     for (i, j) in enumerate(p):
> > >         inverse[j] = i
> > >     return inverse
>
> > Elegant. This seems like the best solution, although it isn't as much
> > fun to write as a "one-liner". Thanks
> >>> invert([1, 2, 3, 1])
>
> [None, 3, 1, 2] #blah

I'm not sure if your post was meant to be serious, but if it was note
that [1,2,3,1] isn't a list which represents a permutation of
0,1,...,n-1 (where n is the length of the list). Ian Kelly's code
works correctly for input of the specified form.

Thread

a better way to invert a list? scattered <tooscattered@gmail.com> - 2011-04-05 14:17 -0700
  Re: a better way to invert a list? Ian Kelly <ian.g.kelly@gmail.com> - 2011-04-05 15:46 -0600
    Re: a better way to invert a list? scattered <tooscattered@gmail.com> - 2011-04-05 16:24 -0700
      Re: a better way to invert a list? Glazner <yoavglazner@gmail.com> - 2011-04-06 01:48 -0700
        Re: a better way to invert a list? scattered <tooscattered@gmail.com> - 2011-04-06 02:48 -0700
        Re: a better way to invert a list? Peter Otten <__peter__@web.de> - 2011-04-06 11:58 +0200
    Re: a better way to invert a list? Raymond Hettinger <python@rcn.com> - 2011-04-05 17:07 -0700
  Re: a better way to invert a list? Paul Rubin <no.email@nospam.invalid> - 2011-04-06 12:51 -0700
    Re: a better way to invert a list? Ian Kelly <ian.g.kelly@gmail.com> - 2011-04-06 14:08 -0600

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