Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!newsreader4.netcologne.de!news.netcologne.de!xlned.com!feeder7.xlned.com!news2.euro.net!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
MIME-Version: 1.0
In-Reply-To: <51C1666F.6050307@davea.name>
References: <kpbraq$qvk$6@news.ntua.gr> <mailman.3184.1371126194.3114.python-list@python.org> <kpckqb$28k2$3@news.ntua.gr> <51ba6e92$0$29997$c3e8da3$5496439d@news.astraweb.com> <kpeio7$p37$7@news.ntua.gr> <kpel54$spl$3@news.ntua.gr> <mailman.3273.1371200264.3114.python-list@python.org> <kpem3e$spl$4@news.ntua.gr> <mailman.3277.1371201144.3114.python-list@python.org> <kpeorl$spl$7@news.ntua.gr> <ro5qr89r11ebtqif6hr9egkkr1s4ecogef@4ax.com> <kpjsfi$hmp$2@news.ntua.gr> <e2e2s8pbfbvequ26icu1avilqjcod48san@4ax.com> <51C144AA.5060008@davea.name> <CAPTjJmomYym6gR6VQLdO+UJ9rK1+YjVZ5+LqBppq_Ls2SXmp7w@mail.gmail.com> <51C1666F.6050307@davea.name>
Date: Wed, 19 Jun 2013 18:21:40 +1000
Subject: Re: A certainl part of an if() structure never gets executed.
From: Chris Angelico <rosuav@gmail.com>
To: python-list@python.org
Content-Type: text/plain; charset=ISO-8859-1
Precedence: list
Newsgroups: comp.lang.python
Message-ID: <mailman.3576.1371630102.3114.python-list@python.org>
Lines: 51
NNTP-Posting-Host: 2001:888:2000:d::a6
Xref: csiph.com comp.lang.python:48698

On Wed, Jun 19, 2013 at 6:06 PM, Dave Angel <davea@davea.name> wrote:
> On 06/19/2013 03:14 AM, Chris Angelico wrote:
>>
>> On Wed, Jun 19, 2013 at 3:42 PM, Dave Angel <davea@davea.name> wrote:
>>>
>>> Names are *one of* the ways we specify which objects are to be used. (We
>>> can
>>> also specify objects via an container and a subscript or slice, or via an
>>> attribute of another object.  And probably another way or two.)
>>
>>
>> But you always have to bootstrap it with either a name.
>
>
> Whatever bootstrap really means in this context.  But if you have myname[3]
> + myname[5], the two objects being added are identified by a subscript
> operation, not just a name.
>
>> Or a literal.
>
>
> A literal is used to create an object, and acts like a temporary name for
> that object, but once again the object being operated on isn't necessarily
> that one. You can subscript and get attributes from a literal as well.
>
>
>> So those are the only two ways to specify which objects are to be
>> used.
>>
>
> That would be a pretty weak language, and it wouldn't be python.
>
>
> Now if you considered "." and "[" as operators, then I could understand your
> point.  But
>    http://docs.python.org/3/reference/lexical_analysis.html#operators
> seems to say differently.
>
> Also see
>    http://docs.python.org/3/reference/expressions.html#primaries

They may not quite be "operators" per se, but the fact is that they're
composites built of primitives. You can't reference an object without
somewhere having either a name or a literal to start it off. Your
example starts with the object identified by the name 'myname', and
the objects referenced by the literals 3 and 5, and builds up from
there. Rebinding 'myname' would change that expression, as would
changing the meanings of 3 or 5, though I don't know of any way to do
the latter :)

ChrisA