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From: Michael Selik <michael.selik@gmail.com>
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Subject: Re: reversed(enumerate(x))
Date: Wed, 20 Jul 2016 20:54:46 -0500
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> On Jul 20, 2016, at 12:42 PM, Ian Kelly <ian.g.kelly@gmail.com> wrote:
> 
>    for i, n in reversed(enumerate(x)): pass
> 
> fails with "TypeError: argument to reversed() must be a sequence".

So make it a sequence:
    for i, n in reversed(list(enumerate(x))): pass

If ``x`` is very large, you can use your zip/range technique to save memory.