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To: python-list@python.org
From: Terry Reedy <tjreedy@udel.edu>
Subject: Re: Skipping decorators in unit tests
Date: Fri, 11 Oct 2013 04:17:39 -0400
References: <525768a5$0$29984$c3e8da3$5496439d@news.astraweb.com> <20131011031319.GA30742@cskk.homeip.net>
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Xref: csiph.com comp.lang.python:56658

On 10/10/2013 11:13 PM, Cameron Simpson wrote:
> On 11Oct2013 02:55, Steven D'Aprano <steve+comp.lang.python@pearwood.info> wrote:

>> def undecorate(f):
>>      """Return the undecorated inner function from function f."""
>>      return f.func_closure[0].cell_contents
>
> Whereas this feels like black magic. Is this portable to any decorated
> function? If so, I'd have hoped it was in the stdlib. If not: black magic.
>
>> And in use:
>>
>> py> f(100)
>> 201
>> py> undecorate(f)(100)
>> 200
>
> All lovely, provided you can convince me that undecorate() is robust.
> (And if you can, I'll certainly be filing it away in my funcutils
> module for later use.)

It only works if the decorator returns a closure with the original 
function as the first member (of func_closure). Often true, but not at 
all a requirement.

-- 
Terry Jan Reedy