Path: csiph.com!usenet.pasdenom.info!aioe.org!news.stack.nl!newsfeed.xs4all.nl!newsfeed5.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 0.014 X-Spam-Evidence: '*H*': 0.97; '*S*': 0.00; 'immutable': 0.09; 'referenced': 0.09; 'url:github': 0.09; 'cc:addr:python-list': 0.10; 'index': 0.13; '(assignment': 0.16; 'constitutes': 0.16; 'list)': 0.16; 'singleton': 0.16; 'value),': 0.16; 'wrote:': 0.17; 'latter': 0.22; 'subject:skip:i 10': 0.22; 'cc:2**0': 0.23; 'cc:addr:python.org': 0.25; 'header:In-Reply-To:1': 0.25; '(as': 0.27; 'received:209.85.210.46': 0.27; 'skip:@ 10': 0.27; 'subject:list': 0.28; 'chris': 0.28; 'run': 0.28; 'unlike': 0.30; '(and': 0.32; 'more,': 0.32; 'problem': 0.33; 'received:google.com': 0.34; 'thanks': 0.34; 'list': 0.35; 'pm,': 0.35; 'received:209.85': 0.35; 'message-id:@gmail.com': 0.36; 'charset:us-ascii': 0.36; 'received:209': 0.37; 'subject:: ': 0.38; 'object': 0.38; 'subject:-': 0.40; 'header:Received:5': 0.40; 'your': 0.60; 'link': 0.60; 'first': 0.61; 'header:Message- Id:1': 0.62; 'clearing': 0.91 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to:x-mailer; bh=AMPluQkrBokcSjFN0dj2l+BzvUbz6884n2RyID8vCAs=; b=hPcFvQSzDy4HNFJl6PzG8e7vIvpUMg6sX00cPv4fkHMfhilkeE4Jrsh3agT6sm7laa y+W09oqL1ao0ogBrAxTg/hUi+T3pJPRV7M8iB8zXNq5eQg6sBhbZSOYMxejXSwa1TCCU mGPX38sF73lAlk5df4JqYvsy/RyQxk1utSPjblnaEO61zoQXWFibJftUMcRRPS1DLrOE q74mD2HiSbSfBW9c6sB9Yw0NJJ3mqW1r/SAzz1yy01QsgHKcOkTJH7hLQqq00mAuCR3j +douuVr29ZMZuX5awAFgovBvA5iovxac4AHtkwX4QhfkG8RK13sV9ATdwzGUoouhah1d da1w== Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 6.2 \(1499\)) Subject: Re: Multi-dimensional list initialization From: Demian Brecht In-Reply-To: Date: Mon, 5 Nov 2012 07:01:55 -0800 Content-Transfer-Encoding: quoted-printable References: To: Chris Rebert X-Mailer: Apple Mail (2.1499) Cc: "python-list@python.org" 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: 21 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1352127722 news.xs4all.nl 6876 [2001:888:2000:d::a6]:56292 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:32774 On 2012-11-04, at 11:07 PM, Chris Rebert wrote: > However, unlike a list object (as in your latter example), the object > `None` is completely immutable (and what's more, a singleton value), > so you just-so-happen *not to be able to* run into the same problem of > mutating an object (assignment to an index of a list constitutes > mutation of that list) that is referenced in multiple places, for you > cannot mutate None in the first place! Thanks for clearing that up Chris (and the link to the FAQ). I had = thought about that after going to bed ("D'oh.. None is immutable.. = *That's* gotta be why"). Demian Brecht @demianbrecht http://demianbrecht.github.com