Groups > comp.lang.python > #22023

Re: Best way to disconnect from ldap?

References	<jkda88$mrk$1@reader1.panix.com> <CAMZYqRQR0VFweQgN8jb3wkx-opabvVQJy5zRtQQrv7tnnzivwA@mail.gmail.com> <CALvWhxvq-KO0ZxMwo-A7ieLyULHh95LAAiLon3zqBgMixZpFbA@mail.gmail.com> <4F6A4D02.6020403@tim.thechases.com> <20120322131447.GG19657@ccapuser-ubuntu.WICOURTS.GOV>
Date	2012-03-22 06:27 -0700
Subject	Re: Best way to disconnect from ldap?
From	Chris Rebert <clp2@rebertia.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.888.1332422868.3037.python-list@python.org> (permalink)

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On Thu, Mar 22, 2012 at 6:14 AM, Tycho Andersen <tycho@tycho.ws> wrote:
> On Wed, Mar 21, 2012 at 04:49:54PM -0500, Tim Chase wrote:
>> On 03/21/12 15:54, Chris Kaynor wrote:
>> >As Chris Rebert pointed out, there is no guarantee as to when the
>> >__del__ method is called. CPython will generally call it immediately,
>> >however if there are reference cycles it may never call it
>>
>> And more maddeningly, modules/objects used/called from within the
>> __del__ may have already gone out of scope, producing
>> head-scratching errors.  I've been bitten by this enough times that
>> I just stopped using __del__ completely.
>
> I've had similar experiences. In fact, in light of all this - why does
> __del__ exist at all? Novice python users may (reasonably) assume it
> behaves similarly to a C++ destructor (even though the docs warn
> otherwise).
>
> Given that you can't trust __del__, is there a legitimate use case for
> it?

Writing resource classes (like `file`) in C? Their __del__()s
typically involve little/less Python-level stuff and thus less
paranoia need be exercised.
There is somewhat of a perverse incentive in having such last-ditch
clean-up mechanisms though. "This code seems to work fine without
`with`, so why bother changing it?"

Cheers,
Chris

Thread

Best way to disconnect from ldap? John Gordon <gordon@panix.com> - 2012-03-21 19:30 +0000
  Re: Best way to disconnect from ldap? "J. Cliff Dyer" <jcd@sdf.lonestar.org> - 2012-03-21 16:21 -0400
  Re: Best way to disconnect from ldap? Chris Rebert <clp2@rebertia.com> - 2012-03-21 13:34 -0700
  Re: Best way to disconnect from ldap? Chris Kaynor <ckaynor@zindagigames.com> - 2012-03-21 13:54 -0700
  Re: Best way to disconnect from ldap? Tycho Andersen <tycho@tycho.ws> - 2012-03-22 08:14 -0500
    Re: Best way to disconnect from ldap? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-03-22 17:26 +0000
      Re: Best way to disconnect from ldap? Tim Chase <python.list@tim.thechases.com> - 2012-03-22 12:54 -0500
      Re: Best way to disconnect from ldap? Terry Reedy <tjreedy@udel.edu> - 2012-03-22 15:27 -0400
      Re: Best way to disconnect from ldap? Tycho Andersen <tycho@tycho.ws> - 2012-03-22 16:02 -0500
  Re: Best way to disconnect from ldap? Chris Rebert <clp2@rebertia.com> - 2012-03-22 06:27 -0700
  Re: Best way to disconnect from ldap? Tycho Andersen <tycho@tycho.ws> - 2012-03-22 09:00 -0500
  Re: Best way to disconnect from ldap? John Gordon <gordon@panix.com> - 2012-04-05 18:38 +0000
    Re: Best way to disconnect from ldap? Michael Ströder <michael@stroeder.com> - 2012-04-05 20:56 +0200

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