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| References | (1 earlier) <jgv9ps$35g$1@dough.gmane.org> <mailman.5558.1328759017.27778.python-list@python.org> <Xns9FF46B35EDFF9duncanbooth@127.0.0.1> <mailman.5588.1328798176.27778.python-list@python.org> <Xns9FF497406322duncanbooth@127.0.0.1> |
|---|---|
| Date | 2012-02-09 10:19 -0500 |
| Subject | Re: frozendict |
| From | Nathan Rice <nathan.alexander.rice@gmail.com> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.5593.1328800790.27778.python-list@python.org> (permalink) |
>> Two dicts created from the same inputs will return items in the same
>> arbitrary order. As long as you don't insert or delete a key you're
>> fine.
>>
> Two dicts that contain the same keys and values may or may not return them
> in the same order:
>
>>>> dict.fromkeys('ia')
> {'i': None, 'a': None}
>>>> dict.fromkeys('ai')
> {'a': None, 'i': None}
>
> Would your system count those two dicts as the same?
>
> If the sequence in which the keys were added to the dict (and deleted if
> appropriate) is exactly the same then it is likely but still not guaranteed
> that they will have the same order. The only ordering guarantee is that
> within a single dict keys and values will appear in a consistent order so
> long as you don't add/delete keys between calls.
As I said, two dictionaries created from the same input will be the
same... 'ai' != 'ia'. If I need to hash a dict that I don't know was
created in a deterministic order, I'd frozenset(thedict.items()).
Nathan
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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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