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Re: using __getitem()__ correctly

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From Ben Finney <ben+python@benfinney.id.au>
Newsgroups comp.lang.python
Subject Re: using __getitem()__ correctly
Date Thu, 31 Dec 2015 10:13:53 +1100
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"Charles T. Smith" <cts.private.yahoo@gmail.com> writes:

> I don't understand this distinction between an "attribute" and a "dict
> item".

When did you most recently work through the Python tutorial
<URL:https://docs.python.org/3/tutorial/>> You may want to work through
it again, from start to finish and exercising each example, to be sure
you have a solid understanding of basic concepts like these.

In brief: Objects have attributes; looking up an attribute on an object
has specific syntax. Dictionaries are collections of items; the items
are looked up by key, using a quite different syntax. Those two
different syntaxes translate to distinct special methods.

You may be familiar with other languages where the distinction between
“attribute of an object” is not distinct from “item in a dictionary”.
Python is not one of those languages; the distinction is real and
important. You'll need to do some remedial learning of Python, and I
recommend working through the Python tutorial.

-- 
 \            “But it is permissible to make a judgment after you have |
  `\    examined the evidence. In some circles it is even encouraged.” |
_o__)                    —Carl Sagan, _The Burden of Skepticism_, 1987 |
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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