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Re: using __getitem()__ correctly

Path csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From Ben Finney <ben+python@benfinney.id.au>
Newsgroups comp.lang.python
Subject Re: using __getitem()__ correctly
Date Thu, 31 Dec 2015 22:51:47 +1100
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"Charles T. Smith" <cts.private.yahoo@gmail.com> 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

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Thread

using __getitem()__ correctly "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2015-12-30 12:57 +0000
  Re: using __getitem()__ correctly Chris Angelico <rosuav@gmail.com> - 2015-12-31 00:11 +1100
    Re: using __getitem()__ correctly "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2015-12-30 14:40 +0000
      Re: using __getitem()__ correctly Ian Kelly <ian.g.kelly@gmail.com> - 2015-12-30 08:35 -0700
        Re: using __getitem()__ correctly "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2015-12-30 16:58 +0000
          Re: using __getitem()__ correctly Ian Kelly <ian.g.kelly@gmail.com> - 2015-12-30 13:40 -0700
            Re: using __getitem()__ correctly "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2015-12-30 22:54 +0000
              Re: using __getitem()__ correctly "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2015-12-30 22:58 +0000
              Re: using __getitem()__ correctly Ben Finney <ben+python@benfinney.id.au> - 2015-12-31 10:13 +1100
                Re: using __getitem()__ correctly "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2015-12-30 23:18 +0000
                Re: using __getitem()__ correctly Steven D'Aprano <steve@pearwood.info> - 2015-12-31 10:50 +1100
                Re: using __getitem()__ correctly Ben Finney <ben+python@benfinney.id.au> - 2015-12-31 11:21 +1100
                Re: using __getitem()__ correctly "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2015-12-31 11:30 +0000
                Re: using __getitem()__ correctly Ben Finney <ben+python@benfinney.id.au> - 2015-12-31 22:51 +1100
                Re: using __getitem()__ correctly Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2015-12-31 12:12 +0000
                Re: using __getitem()__ correctly "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2015-12-31 13:39 +0000
                Re: using __getitem()__ correctly Steven D'Aprano <steve@pearwood.info> - 2016-01-01 02:03 +1100
                Re: using __getitem()__ correctly "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2015-12-31 11:17 +0000
                Re: using __getitem()__ correctly Steven D'Aprano <steve@pearwood.info> - 2016-01-01 01:43 +1100
              Re: using __getitem()__ correctly Ian Kelly <ian.g.kelly@gmail.com> - 2015-12-30 17:31 -0700
                Re: using __getitem()__ correctly "Charles T. Smith" <cts.private.yahoo@gmail.com> - 2015-12-31 12:45 +0000

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