Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Ben Finney Newsgroups: comp.lang.python Subject: Re: using __getitem()__ correctly Date: Thu, 31 Dec 2015 22:51:47 +1100 Lines: 36 Message-ID: References: <56846ddf$0$1601$c3e8da3$5496439d@news.astraweb.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: news.uni-berlin.de E2iDQB6zDJSFcqufDysHtAnZYKg9Geja5CMDt5gzr09Q== Cancel-Lock: sha1:LsfLMX7PxogPDF6cUkf/swqabCw= 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; 'python,': 0.02; 'attributes': 0.07; 'important,': 0.07; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'subject:()': 0.09; 'subject:using': 0.09; 'thu,': 0.15; 'attributes,': 0.16; 'attributes.': 0.16; 'justin': 0.16; 'magic': 0.16; 'received:80.91.229.3': 0.16; 'received:io': 0.16; 'received:plane.gmane.org': 0.16; 'received:psf.io': 0.16; 'smith"': 0.16; 'wrote:': 0.16; '2015': 0.20; 'meant': 0.22; 'year,': 0.22; 'dec': 0.23; 'header:User-Agent:1': 0.26; 'header:X -Complaints-To:1': 0.26; 'dictionary': 0.29; 'implied': 0.29; 'methods.': 0.29; 'items.': 0.33; 'clear': 0.35; 'but': 0.36; 'to:addr:python-list': 0.36; 'subject:: ': 0.37; 'really': 0.37; 'received:org': 0.37; 'mean': 0.38; 'end': 0.39; 'why': 0.39; 'to:addr:python.org': 0.40; 'relationship': 0.61; 'hope': 0.61; 'course': 0.62; 'above,': 0.63; 'between': 0.65; 'skip:\xe2 10': 0.70; '8bit%:40': 0.72; '8bit%:43': 0.72; '8bit%:46': 0.76; '_o__)': 0.84; 'difference.': 0.84; 'received:125': 0.84 X-Injected-Via-Gmane: http://gmane.org/ 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) 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: , Xref: csiph.com comp.lang.python:101051 "Charles T. Smith" writes: > On Thu, 31 Dec 2015 11:21:59 +1100, Ben Finney wrote: > > > Tersely: the relationship between an object and its attributes, is > > not the same as the relationship between a dictionary and its items. > > I understand this to mean that the relationship between a dictionary > and its items is less complex than the relationship between an object > and its attributes. That's not implied by the above, nor is it what I meant. I meant that the relationship is not the same. * The attributes of an object ‘foo’ are what you access via ‘foo.bar’ syntax. You don't access those attributes via ‘foo[bar]’. * The items of a dictionary ‘foo’ are what you access via ‘foo[bar]’ syntax. You don't access those items via ‘foo.bar’. That's an important, and real, difference. And it's much better learned as part of a comprehensive course on Python, not in a deep dive into the magic methods. I really don't know why it's been so difficult to talk about this, but I hope my meaning is clear now. Have a wonderful end of year, folks. -- \ “There are no chaplains in foxholes.” —Sergeant Justin | `\ Griffith, 2011-07-27 | _o__) | Ben Finney