Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.freenet.ag!news2.euro.net!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 0.051 X-Spam-Evidence: '*H*': 0.90; '*S*': 0.00; 'arguments': 0.09; 'caller': 0.09; 'python': 0.11; 'jan': 0.12; 'suggest': 0.14; 'attributes,': 0.16; 'attributes.': 0.16; 'metaclass': 0.16; 'subject:their': 0.16; 'wrote:': 0.18; 'all,': 0.19; 'passing': 0.19; 'solution.': 0.20; 'work,': 0.20; 'seems': 0.21; 'creating': 0.23; 'header:User-Agent:1': 0.23; "i've": 0.25; 'this:': 0.26; 'header:In-Reply-To:1': 0.27; 'bunch': 0.31; 'anyone': 0.31; 'class': 0.32; 'problem': 0.35; 'classes': 0.35; 'something': 0.35; 'but': 0.35; 'add': 0.35; 'there': 0.35; 'explains': 0.36; 'instances': 0.36; 'returning': 0.36; 'doing': 0.36; 'hi,': 0.36; 'url:org': 0.36; 'example,': 0.37; 'to:addr:python-list': 0.38; 'does': 0.39; 'to:addr:python.org': 0.39; 'how': 0.40; 'even': 0.60; 'such': 0.63; 'different': 0.65; 'here': 0.66; 'header :Reply-To:1': 0.67; 'reply-to:no real name:2**0': 0.71; 'decorate': 0.84; 'url:video': 0.84; 'received:89': 0.85; 'demand': 0.91 Date: Wed, 03 Apr 2013 08:06:11 +0300 From: Jan Riechers User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130307 Thunderbird/17.0.4 MIME-Version: 1.0 To: python-list@python.org Subject: Re: Decorating functions without losing their signatures References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list Reply-To: janpeterr@freenet.de 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: 26 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1364966074 news.xs4all.nl 6904 [2001:888:2000:d::a6]:52738 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:42628 On 03.04.2013 04:05, Rotwang wrote: > Hi all, > > Here's a Python problem I've come up against and my crappy solution. > Hopefully someone here can suggest something better. I want to decorate > a bunch of functions with different signatures; for example, I might > want to add some keyword-only arguments to all functions that return > instances of a particular class so that the caller can create instances > with additional attributes. So I do something like this: [...] > It seems to work, but I don't like it. Does anyone know of a better way > of doing the same thing? Hi, I think you might want to check out that Pycon2013 Video about Metaclass Prgoramming of David Beazley: http://www.pyvideo.org/video/1716/python-3-metaprogramming He explains how to passing attributes, such creating custom classes on demand and returning there signatures even when wrapped. I think that was what you wanted to archive? Regards Jan