Path: csiph.com!eternal-september.org!feeder.eternal-september.org!border1.nntp.ams1.giganews.com!nntp.giganews.com!newsfeed.xs4all.nl!newsfeed7.news.xs4all.nl!nzpost1.xs4all.net!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.005 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'context': 0.05; 'differently': 0.07; '[1,': 0.09; 'behave': 0.09; 'called.': 0.09; 'interpreter,': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'throw': 0.09; 'python': 0.10; 'output': 0.13; 'interpreter': 0.15; '999': 0.16; 'bind': 0.16; 'goal,': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'space;': 0.16; 'exists': 0.18; 'function,': 0.22; "i've": 0.25; 'header:User-Agent:1': 0.26; 'header:X-Complaints-To:1': 0.26; 'function': 0.28; 'obscure': 0.29; 'prints': 0.29; 'branch': 0.30; 'morning': 0.32; "d'aprano": 0.33; 'steven': 0.33; "i'll": 0.33; 'me?': 0.34; 'except': 0.34; 'so,': 0.35; 'possible,': 0.35; "isn't": 0.35; 'sometimes': 0.35; 'but': 0.36; 'possible.': 0.36; 'to:addr:python-list': 0.36; 'subject:: ': 0.37; 'being': 0.37; 'received:org': 0.37; 'things': 0.38; 'subject:-': 0.39; 'to:addr:python.org': 0.40; 'some': 0.40; 'software': 0.40; 'chance': 0.60; 'ever': 0.60; 'your': 0.60; 'skip:n 10': 0.62; 'purchase': 0.66; 'warm': 0.67; 'skip:\xe2 10': 0.70; 'wish': 0.71; '_o__)': 0.84; 'pray': 0.84; 'received:125': 0.84; 'skin': 0.91; 'thing,': 0.93 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Ben Finney Subject: Re: Context-aware return Date: Fri, 11 Sep 2015 04:12:53 +1000 References: <55f1c3c6$0$1659$c3e8da3$5496439d@news.astraweb.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Gmane-NNTP-Posting-Host: jigong.madmonks.org X-Public-Key-ID: 0xAC128405 X-Public-Key-Fingerprint: 517C F14B B2F3 98B0 CB35 4855 B8B2 4C06 AC12 8405 X-Public-Key-URL: http://www.benfinney.id.au/contact/bfinney-pubkey.asc X-Post-From: Ben Finney User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux) Cancel-Lock: sha1:ElTTLdSyAqdqQgzlvZIOYKILKz4= X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.20+ 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: 40 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1441908814 news.xs4all.nl 23856 [2001:888:2000:d::a6]:54602 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:96276 Steven D'Aprano writes: > I have a function which is intended for use at the interactive > interpreter, but may sometimes be used non-interactively. I wish to > change it's output depending on the context of how it is being called. > […] > > x = func() > assert x == 999 > > L = [1, 2, func(), 4] > assert L[2] == 999 > > func() > # interactive interpreter prints "Awesome" > > Is such a thing possible, and if so, how would I do it? That makes my skin creep. In the name of all the tea I've sacrificed to Python over the years, I pray this isn't possible. > If I did this thing, would people follow me down the street booing and > jeering and throwing things at me? First thing in the morning I will purchase a head of cabbage and store it in a warm place to make it rot, on the off chance you find some obscure way to achieve your benighted goal, just so I can be first in line to throw it as you pass. If ever I have to worry that some arbitrary Python function, unbenownst to me, might have a branch that will make it behave differently depending on *whether I bind a reference to its return value*, then I'll know you are sent to us as an evil spirit to make all software suck. -- \ “Nothing exists except atoms and empty space; everything else | `\ is opinion.” —Democritus | _o__) | Ben Finney