Path: csiph.com!newsfeed.hal-mli.net!feeder3.hal-mli.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!newsfeed.xs4all.nl!newsfeed2a.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.006 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'subject:: [': 0.04; 'resulting': 0.04; 'explicit': 0.07; 'cc:addr:python-list': 0.11; 'python': 0.11; '__del__': 0.16; 'called.': 0.16; 'deleted;': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'subject: \n ': 0.16; 'subject:Baypiggies': 0.16; 'wrote:': 0.18; 'alex': 0.19; 'subject:] ': 0.20; 'feb': 0.22; 'cc:addr:python.org': 0.22; 'entries': 0.24; 'cc:2**0': 0.24; 'query': 0.26; 'header:In-Reply-To:1': 0.27; "doesn't": 0.30; 'message-id:@mail.gmail.com': 0.30; '25,': 0.31; 'object.': 0.31; 'table': 0.34; 'subject:the': 0.34; "can't": 0.35; 'but': 0.35; 'received:google.com': 0.35; 'should': 0.36; 'two': 0.37; 'being': 0.38; 'pm,': 0.38; 'that,': 0.38; 'system.': 0.39; 'guarantee': 0.63; 'name': 0.63; 'kind': 0.63; 'removal': 0.74; 'subject:Class': 0.91; 'to:none': 0.92 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:cc :content-type; bh=OWfeoG8B2Gkbf4HuATGKu/VFGKk21BzXQEMUv7sdL10=; b=uXbDDR9k2Yx41rCds1a/eR5sOSbbaak0e+UZeoRJUS240BdRNZyF21jeXXttkNIdZw HOGbXaWPL3T1JMfhIfRyFezScVFhlmy7c9xSD3iEoD4/vBin4T3MtXSVaSpTagogFjI0 cUK6EwsZ79tUtoDSlHfOVs5v36v9GqVBOZTpgoxfI02MgNy5HTPZUQQAsUrimrM20yyw cHBVgaPuFVXrBvY//jT4mWLbQ70t7ieaq8ZdJk0JpJAjcPS9CPe0LWL9LLDqLAPtsrgp uvKbyDvbTsok9N7lcA+XhuDcJEuZmDsJZlvrIXP04WTFuM9OIOEwkgf2ANYvvaOKU57R RAIA== MIME-Version: 1.0 X-Received: by 10.68.112.164 with SMTP id ir4mr3290219pbb.153.1393295695395; Mon, 24 Feb 2014 18:34:55 -0800 (PST) In-Reply-To: References: Date: Tue, 25 Feb 2014 13:34:55 +1100 Subject: Re: [Baypiggies] Class decorator to capture the creation and deletion of objects From: Chris Angelico Cc: "python-list@python.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 18 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1393295699 news.xs4all.nl 2929 [2001:888:2000:d::a6]:35751 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:67015 On Tue, Feb 25, 2014 at 1:24 PM, Alex Martelli wrote: > del a1 > del a2 > del a3 > del b1 > del b2 > > At this point, all entries in the table should be deleted; query should > return an empty list! > You can't actually depend on del resulting in __del__ being called. The two are tangentially related, but Python doesn't guarantee that unbinding a name will result in the destruction of the object. I recommend that, instead, you have some kind of explicit removal system. ChrisA