Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!news.dougwise.org!nntpfeed.proxad.net!proxad.net!feeder1-1.proxad.net!feeder.news-service.com!newsfeed.xs4all.nl!newsfeed6.news.xs4all.nl!xs4all!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 0.021 X-Spam-Evidence: '*H*': 0.96; '*S*': 0.00; 'instance,': 0.05; 'terry': 0.07; 'wrapper': 0.07; 'bind': 0.09; 'dict': 0.09; 'says,': 0.09; 'stuff!': 0.09; 'am,': 0.14; 'wrote:': 0.14; 'dictionary,': 0.16; 'indefinitely': 0.16; 'instance:': 0.16; 'methods,': 0.16; 'reedy': 0.16; 'method.': 0.19; 'header:In-Reply-To:1': 0.22; 'itself.': 0.22; 'objects': 0.24; 'creating': 0.26; 'chris': 0.27; 'message-id:@mail.gmail.com': 0.28; 'thanks': 0.29; 'sat,': 0.29; 'bound': 0.29; 'it.': 0.31; 'to:addr:python-list': 0.32; 'created': 0.33; 'thinking': 0.33; 'lines': 0.34; 'reference': 0.34; 'normally': 0.35; 'too': 0.36; 'some': 0.37; 'case': 0.37; 'self': 0.37; 'received:209.85': 0.37; 'apr': 0.38; 'received:google.com': 0.38; 'pretty': 0.38; 'unless': 0.38; 'to:addr:python.org': 0.39; 'subject: (': 0.39; 'received:209': 0.39; 'would': 0.40; "it's": 0.40; 'header:Received:5': 0.40; 'subject': 0.61; '2011': 0.62; 'special': 0.66; 'details.': 0.67; 'subject:The': 0.69; 'kept': 0.73; 'loves': 0.73; '__call__': 0.84; 'common,': 0.84; 'received:209.85.210.174': 0.84; 'received :mail-iy0-f174.google.com': 0.84 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=w8Y+lmJAfYL+dU+DhvSzLcyPomr19JHn2vUNmU7luu8=; b=QttPSitWHEJ3rUbzqBiJO4z5rAPbIb/h1LZ0fPzbdJ1wGwHznqcrf/vTGkpNzoZz+S 41hNT2BfvvUsEVPlKughTEsiJ7PQf8sbCRlA6rRMPAFm7pJTKBrQG18BSevo6NdoE8Ou 0H57CNM+NKSIIh27r1V5wcdtBgFZ1gSjwQlFE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=WrULZem5MVUJO4OThjIgN8qN1z5c9RCcRD2JM0tKc8pX9m7yizJSBpmiaV0XUluZhM 0a3uNrnO0cRcSvWmhLvbuSaLTZ14GWz6WpxLXb4nbH+BP67L9fTiOCjY8r9EHUc42FlR REY6sK5VVk3BniCzqX0ohQ5pMqRzKsSinoKio= MIME-Version: 1.0 In-Reply-To: References: <4D95EA23.10802@aim.com> Date: Sat, 2 Apr 2011 13:21:06 +1100 Subject: Re: The Magick of __call__ (Or, Digging Deeper Than I Ought To) From: Chris Angelico To: python-list@python.org Content-Type: text/plain; charset=ISO-8859-1 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.12 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: 27 NNTP-Posting-Host: 82.94.164.166 X-Trace: 1301710869 news.xs4all.nl 81484 [::ffff:82.94.164.166]:39663 X-Complaints-To: abuse@xs4all.nl Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:2423 Thanks for those explanations! As Corey's original subject says, this IS digging pretty deep into implementation details. My geekly side loves that though! On Sat, Apr 2, 2011 at 8:35 AM, Terry Reedy wrote: > Every time a method is accessed through an instance, a new wrapper is > created. Why? 1. If you want to reuse a bound methods, just bind it to a > name or something and reuse it. 2. To automatically keep it for possible > reuse, which normally is not too common, it wold have to be kept in some > hidden dict which would grow indefinitely unless pruned occasionally. What I was thinking was something along the lines of a loop-back reference in the wrapper itself. So for instance: Foo.__call__ = wrapper(Foo) The wrapper would be created with a __call__ method of itself: self.__call__ = self That would not require a dictionary, it's just a special case of creating the __call__ method. Since, apparently, we can "go infinite" with the __call__ dereferencing, these objects must be created when referenced? Fascinating stuff! Chris Angelico