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Re: Skipping decorators in unit tests

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On 10/11/2013 4:17 AM, Terry Reedy wrote:
> 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.

Another standard decorator method is to write a class with a .__call__ 
method and attach the original function to instances as an attribute. 
(Indeed, decorators were borrowed from class-happy Java ;-). But there 
is no standard as to what the function attribute of instances is called. 
The OP's request for accessing the function without modifying the tested 
code cannot be met in general. One must have access to the tested code.


-- 
Terry Jan Reedy

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Thread

Skipping decorators in unit tests Gilles Lenfant <gilles.lenfant@gmail.com> - 2013-10-10 07:00 -0700
  Re: Skipping decorators in unit tests Cameron Simpson <cs@zip.com.au> - 2013-10-11 09:12 +1100
    Re: Skipping decorators in unit tests Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-11 02:55 +0000
      Re: Skipping decorators in unit tests Cameron Simpson <cs@zip.com.au> - 2013-10-11 14:13 +1100
        Re: Skipping decorators in unit tests Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-11 04:36 +0000
          Re: Skipping decorators in unit tests Terry Reedy <tjreedy@udel.edu> - 2013-10-11 04:23 -0400
      Re: Skipping decorators in unit tests Ben Finney <ben+python@benfinney.id.au> - 2013-10-11 14:42 +1100
      Re: Skipping decorators in unit tests Terry Reedy <tjreedy@udel.edu> - 2013-10-11 04:17 -0400
      Re: Skipping decorators in unit tests Terry Reedy <tjreedy@udel.edu> - 2013-10-11 04:25 -0400
      Re: Skipping decorators in unit tests Terry Reedy <tjreedy@udel.edu> - 2013-10-11 04:32 -0400
      Re: Skipping decorators in unit tests Ethan Furman <ethan@stoneleaf.us> - 2013-10-11 10:51 -0700
  Re: Skipping decorators in unit tests Ned Batchelder <ned@nedbatchelder.com> - 2013-10-10 19:44 -0400
  Re: Skipping decorators in unit tests Terry Reedy <tjreedy@udel.edu> - 2013-10-10 21:12 -0400
  Re: Skipping decorators in unit tests Gilles Lenfant <gilles.lenfant@gmail.com> - 2013-10-11 02:37 -0700
    Re: Skipping decorators in unit tests Cameron Simpson <cs@zip.com.au> - 2013-10-12 08:38 +1100

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