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Date: Fri, 3 Jan 2014 11:07:58 +1100
Subject: Re: Ifs and assignments
From: Chris Angelico <rosuav@gmail.com>
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Xref: csiph.com comp.lang.python:63011

On Fri, Jan 3, 2014 at 11:06 AM, Chris Angelico <rosuav@gmail.com> wrote:
> Pass any object through truth() and it'll either stay the same (if
> it's true) or become this object (if it's false). You can then carry
> on with other method calls, and they'll all happily return false.
>
> result = (
>     truth(re1.match(string)).group(0) or
>     truth(re2.match(string)).group(0) or
>     truth(re3.match(string)).group(0) or
>     default_value
> )

Oh, just thought of a possible snag. Since an empty string comes up as
false, this exact notation would fail if the re can match nothing. But
you probably know if it's possible for that to happen, so don't use
this simple short-hand. :)

ChrisA