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Re: frozendict

References (5 earlier) <Xns9FF497406322duncanbooth@127.0.0.1> <CAOFbRmJLyNA=-oM3eyASVE0EzA6SrjguP7Lv1Vsj2qA4=qU-cw@mail.gmail.com> <mailman.5597.1328805384.27778.python-list@python.org> <4f3471e9$0$29986$c3e8da3$5496439d@news.astraweb.com> <CAOFbRmJN=XicYeUjN9+a800FqvRGigA4p_88mU=Pj1ZRtcgwfw@mail.gmail.com>
Date 2012-02-10 21:08 +1100
Subject Re: frozendict
From Chris Angelico <rosuav@gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.5645.1328868491.27778.python-list@python.org> (permalink)

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On Fri, Feb 10, 2012 at 1:30 PM, Nathan Rice
<nathan.alexander.rice@gmail.com> wrote:
> The only thing needed to avoid the hash collision is that your hash
> function is not not 100% predictable just by looking at the python
> source code.  I don't see why every dict would have to be created
> differently.  I would think having the most ubiquitous data structure
> in your language be more predictable would be a priority.  Oh well....

It's perfectly predictable. If you put a series of keys into it, you
get those same keys back. Nobody ever promised anything about order.

If your hash function is not 100% predictable, that means it varies on
the basis of something that isn't part of either the Python
interpreter or the script being run. That means that, from one
execution to another of the exact same code, the results could be
different. The keys will come out in different orders.

ChrisA

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Re: frozendict Nathan Rice <nathan.alexander.rice@gmail.com> - 2012-02-08 22:43 -0500
  Re: frozendict Duncan Booth <duncan.booth@invalid.invalid> - 2012-02-09 10:33 +0000
    Re: frozendict Nathan Rice <nathan.alexander.rice@gmail.com> - 2012-02-09 09:36 -0500
      Re: frozendict Duncan Booth <duncan.booth@invalid.invalid> - 2012-02-09 14:52 +0000
        Re: frozendict Nathan Rice <nathan.alexander.rice@gmail.com> - 2012-02-09 10:19 -0500
          Re: frozendict Duncan Booth <duncan.booth@invalid.invalid> - 2012-02-09 18:47 +0000
        Re: frozendict Ian Kelly <ian.g.kelly@gmail.com> - 2012-02-09 09:35 -0700
          Re: frozendict Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-02-10 01:24 +0000
            Re: frozendict Nathan Rice <nathan.alexander.rice@gmail.com> - 2012-02-09 21:30 -0500
            Re: frozendict Terry Reedy <tjreedy@udel.edu> - 2012-02-09 22:33 -0500
            Re: frozendict Chris Angelico <rosuav@gmail.com> - 2012-02-10 21:08 +1100
            Re: frozendict Nathan Rice <nathan.alexander.rice@gmail.com> - 2012-02-10 11:53 -0500
            Re: frozendict Chris Rebert <clp2@rebertia.com> - 2012-02-10 09:00 -0800
            Re: frozendict Nathan Rice <nathan.alexander.rice@gmail.com> - 2012-02-10 13:14 -0500
              Re: frozendict John Nagle <nagle@animats.com> - 2012-02-10 10:57 -0800
                Re: frozendict 88888 Dihedral <dihedral88888@googlemail.com> - 2012-02-10 21:52 -0800
                Re: frozendict John Nagle <nagle@animats.com> - 2012-02-13 13:15 -0800
        Re: frozendict Nathan Rice <nathan.alexander.rice@gmail.com> - 2012-02-09 11:50 -0500

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