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From: Paul Rubin <no.email@nospam.invalid>
Newsgroups: comp.lang.python
Subject: Re: a better way to invert a list?
References: <2215eefd-3677-4459-8656-aa04978f6f3f@g7g2000pro.googlegroups.com>
Date: Wed, 06 Apr 2011 12:51:32 -0700
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Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:2718

scattered <tooscattered@gmail.com> writes:
> def invert(p):
> 	return [ j for (i,j) in sorted(zip(p,range(len(p))))]


   return [j for i,j in sorted(enumerate(p), key=itemgetter(1))]

looks a little cleaner to me.

    In Haskell or ML, you can use patterns that contain wild
    cards that play a role in the pattern-matching but don't establish any
    binding. Can that be done in Python?

Not as much.  You could say something like

         sorted(enumerate(p), key=lambda(_,j): j)

which gets the meaning across (it binds the symbol "_" though this
doesn't escape the lambda).