Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed4.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 0.003 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'assign': 0.07; 'assignment': 0.07; 'assigning': 0.09; 'item,': 0.09; 'python': 0.11; 'def': 0.12; 'jan': 0.12; 'attribute,': 0.16; 'dictionary,': 0.16; 'from:addr:mrabarnett.plus.com': 0.16; 'from:addr:python': 0.16; 'from:name:mrab': 0.16; 'func': 0.16; 'message- id:@mrabarnett.plus.com': 0.16; 'name):': 0.16; 'normally,': 0.16; 'received:192.168.1.4': 0.16; 'skip:@ 20': 0.16; 'slight': 0.16; 'subject:def': 0.16; 'subscripted': 0.16; 'wrote:': 0.18; 'command': 0.22; 'header:User-Agent:1': 0.23; 'skip:" 30': 0.26; 'pass': 0.26; 'header:In-Reply-To:1': 0.27; 'function': 0.29; 'chris': 0.29; 'am,': 0.29; "doesn't": 0.30; 'skip:@ 10': 0.30; 'asked': 0.31; 'that.': 0.31; '25,': 0.31; 'class': 0.32; 'sense': 0.34; 'skip:_ 10': 0.34; 'skip:d 20': 0.34; 'really': 0.36; 'represent': 0.38; 'to:addr:python-list': 0.38; 'to:addr:python.org': 0.39; 'easy': 0.60; "you're": 0.61; 'different': 0.65; '2015': 0.84; 'ethan': 0.84; 'furman': 0.84; 'subject:Alternative': 0.84; 'theme:': 0.84; 'wine': 0.91 X-CM-Score: 0.00 X-CNFS-Analysis: v=2.1 cv=Ev9crEsA c=1 sm=1 tr=0 a=0nF1XD0wxitMEM03M9B4ZQ==:117 a=0nF1XD0wxitMEM03M9B4ZQ==:17 a=0Bzu9jTXAAAA:8 a=Vhvw94NMJWsA:10 a=IkcTkHD0fZMA:10 a=EBOSESyhAAAA:8 a=7SpvC85Faqw2NEVBsdsA:9 a=QEXdDO2ut3YA:10 X-AUTH: mrabarnett@:2500 Date: Sat, 24 Jan 2015 20:35:41 +0000 From: MRAB User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: python-list@python.org Subject: Re: Alternative to multi-line lambdas: Assign-anywhere def statements References: <54C3EAD1.2010501@stoneleaf.us> In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit 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: 52 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1422131752 news.xs4all.nl 2837 [2001:888:2000:d::a6]:55149 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:84490 On 2015-01-24 19:55, Chris Angelico wrote: > On Sun, Jan 25, 2015 at 5:56 AM, Ethan Furman wrote: >> If the non-generic is what you're concerned about: >> >> # not tested >> dispatch_table_a = {} >> dispatch_table_b = {} >> dispatch_table_c = {} >> >> class dispatch: >> def __init__(self, dispatch_table): >> self.dispatch = dispatch_table >> def __call__(self, func): >> self.dispatch[func.__name__] = func >> return func >> >> @dispatch(dispatch_table_a) >> def foo(...): >> pass > > That's still only able to assign to a key of a dictionary, using the > function name. There's no way to represent fully arbitrary assignment > in Python - normally, you can assign to a name, an attribute, a > subscripted item, etc. (Augmented assignment is a different beast > altogether, and doesn't really make sense with functions.) There's no > easy way to say "@stash(dispatch_table_a['asdf'])" and have that end > up assigning to exactly that. > Here's a slight variation on the theme: class DispatchTable(dict): def __call__(self, name): def setter(func): self[name] = func return func return setter command = DispatchTable() @command("foo") def _(*args): print("You asked to foo.") @command("bar") def _(*args): print("There's no wine in the bar.") @command("asdf") def _(*args): print("Asdf! Asdf!")