Re: Dictionary sorting

References	<16245908.783.1320346014867.JavaMail.geo-discussion-forums@yqhd1> <j8v1h5$4mc$1@dough.gmane.org> <4EB31D52.3080707@tim.thechases.com>
Date	2011-11-04 10:59 +1100
Subject	Re: Dictionary sorting
From	Chris Angelico <rosuav@gmail.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.2420.1320364788.27778.python-list@python.org> (permalink)

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On Fri, Nov 4, 2011 at 10:01 AM, Tim Chase
<python.list@tim.thechases.com> wrote:
>  list1 = list(d.iterkeys())
>  list2 = list(d.iterkeys())
>  assert list1 == list2
>

There is such a guarantee in Python 2. From
http://docs.python.org/library/stdtypes.html:
"If items(), keys(), values(), iteritems(), iterkeys(), and
itervalues() are called with no intervening modifications to the
dictionary, the lists will directly correspond. This allows the
creation of (value, key) pairs using zip(): pairs = zip(d.values(),
d.keys()). The same relationship holds for the iterkeys() and
itervalues() methods: pairs = zip(d.itervalues(), d.iterkeys())
provides the same value for pairs. Another way to create the same list
is pairs = [(v, k) for (k, v) in d.iteritems()]."

Python 3 does things quite differently (with views), and I can't find
a corresponding promise, but I expect that this would still be the
case.

ChrisA

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Thread

Dictionary sorting Scott Ware <scottdware@gmail.com> - 2011-11-03 11:46 -0700
  Re: Dictionary sorting John Gordon <gordon@panix.com> - 2011-11-03 18:57 +0000
    Re: Dictionary sorting Scott Ware <scottdware@gmail.com> - 2011-11-03 12:00 -0700
      Re: Dictionary sorting Chris Kaynor <ckaynor@zindagigames.com> - 2011-11-03 12:13 -0700
  Re: Dictionary sorting insomnia@gmail.com - 2011-11-03 13:01 -0700
  Re: Dictionary sorting Terry Reedy <tjreedy@udel.edu> - 2011-11-03 17:36 -0400
  Re: Dictionary sorting Tim Chase <python.list@tim.thechases.com> - 2011-11-03 18:01 -0500
    Re: Dictionary sorting Ben Finney <ben+python@benfinney.id.au> - 2011-11-04 11:06 +1100
      Re: Dictionary sorting Hrvoje Niksic <hniksic@xemacs.org> - 2011-11-04 11:20 +0100
        Re: Dictionary sorting Ben Finney <ben+python@benfinney.id.au> - 2011-11-04 23:19 +1100
  Re: Dictionary sorting Chris Angelico <rosuav@gmail.com> - 2011-11-04 10:59 +1100

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