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Groups > comp.lang.python > #106023
| From | Chris Angelico <rosuav@gmail.com> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Suggestion: make sequence and map interfaces more similar |
| Date | 2016-03-30 11:56 +1100 |
| Message-ID | <mailman.174.1459299768.28225.python-list@python.org> (permalink) |
| References | (1 earlier) <mailman.92.1459101740.28225.python-list@python.org> <56f8836b$0$1602$c3e8da3$5496439d@news.astraweb.com> <56FA8C71.4050306@rece.vub.ac.be> <CAPTjJmqjgnDvzS7=_YRf+T78GYz7J26FzWGfwrygYLeq2E9FeA@mail.gmail.com> <CABbU2U9m-35UqK5KqRj7Y_oLdq_dgH3_EScLb4Sf3UNB4oCgmQ@mail.gmail.com> |
On Wed, Mar 30, 2016 at 9:29 AM, Marco Sulla via Python-list
<python-list@python.org> wrote:
> On 29 March 2016 at 16:31, Chris Angelico <rosuav@gmail.com> wrote:
>> But the definition of a sequence, and likewise the definition of a
>> mapping, goes deeper than that. A sequence has *relative* stability;
>> if one item is at a lower index than another, it will continue to be
>> at a lower index, until you change one of those two items. Changes
>> elsewhere in the sequence might bring them closer together or push
>> them further apart, but one of them is still earlier in the sequence
>> than the other. A mapping, on the other hand, has *absolute*
>> stability. Any given key->value relationship is stable in and of
>> itself. If you stuff a thing into a dict under a particular key, you
>> expect to be able to get it back using that key, not some other.
>
> It's the same arguments of Steven D'Aprano. Let me counter these
> arguments with this example:
>
>>>> class StrangeDict(dict):
> ... def insert(self, k, v):
> ... if k in self:
> ... for key in [x for x in sorted(self.keys()) if x >= k]:
> ... v_next = self[key]
> ... self[key] = v
> ... v = v_next
> ...
> ... self[key+1] = v
> ...
>>>> a = StrangeDict({0:5, 1:7, 2: 14})
>>>> a.insert(1, 5)
>>>> a
> {0: 5, 1: 5, 2: 7, 3: 14}
>
> Yes, it's a terrible class and lacks a lot of safety checks, but I
> don't think at all it violates the map contract. You can continue and
> add some constraint at __init__() about key types and their
> contiguity, some other methods and voila', you'll get a list-like
> class.
The map contract is this:
x = StrangeDict()
x[123] = 456
...
assert x[123] == 456
Your mapping does violate the map contract.
ChrisA
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Re: Suggestion: make sequence and map interfaces more similar "Marco S." <mail.python.org@marco.sulla.e4ward.com> - 2016-03-27 20:01 +0200
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve@pearwood.info> - 2016-03-28 12:05 +1100
Re: Suggestion: make sequence and map interfaces more similar Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2016-03-29 16:08 +0200
Re: Suggestion: make sequence and map interfaces more similar Chris Angelico <rosuav@gmail.com> - 2016-03-30 01:31 +1100
Re: Suggestion: make sequence and map interfaces more similar Marco Sulla <mail.python.org@marco.sulla.e4ward.com> - 2016-03-30 00:29 +0200
Re: Suggestion: make sequence and map interfaces more similar Terry Reedy <tjreedy@udel.edu> - 2016-03-29 20:55 -0400
Re: Suggestion: make sequence and map interfaces more similar Chris Angelico <rosuav@gmail.com> - 2016-03-30 11:56 +1100
Re: Suggestion: make sequence and map interfaces more similar Random832 <random832@fastmail.com> - 2016-03-29 23:38 -0400
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2016-03-30 16:43 +1100
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2016-03-30 16:57 +1100
Re: Suggestion: make sequence and map interfaces more similar Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-30 10:12 +0300
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve@pearwood.info> - 2016-03-30 21:17 +1100
Re: Suggestion: make sequence and map interfaces more similar Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-30 13:28 +0300
Re: Suggestion: make sequence and map interfaces more similar Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2016-03-30 12:34 +0200
Re: Suggestion: make sequence and map interfaces more similar Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-30 13:57 +0300
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve@pearwood.info> - 2016-03-30 23:22 +1100
Re: Suggestion: make sequence and map interfaces more similar Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2016-03-30 15:12 +0200
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve@pearwood.info> - 2016-03-31 02:56 +1100
Re: Suggestion: make sequence and map interfaces more similar Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2016-03-30 21:07 +0200
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve@pearwood.info> - 2016-03-31 13:40 +1100
Re: Suggestion: make sequence and map interfaces more similar Paul Rubin <no.email@nospam.invalid> - 2016-03-30 19:45 -0700
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2016-03-31 17:45 +1100
Re: Suggestion: make sequence and map interfaces more similar Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2016-03-31 09:52 +0200
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve@pearwood.info> - 2016-03-31 21:36 +1100
Re: Suggestion: make sequence and map interfaces more similar Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2016-03-31 12:51 +0200
Re: Suggestion: make sequence and map interfaces more similar Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2016-03-31 13:22 +0200
Re: Suggestion: make sequence and map interfaces more similar Chris Angelico <rosuav@gmail.com> - 2016-03-31 22:57 +1100
Re: Suggestion: make sequence and map interfaces more similar Marko Rauhamaa <marko@pacujo.net> - 2016-03-31 15:36 +0300
Re: Suggestion: make sequence and map interfaces more similar Chris Angelico <rosuav@gmail.com> - 2016-03-31 23:48 +1100
Re: Suggestion: make sequence and map interfaces more similar Marko Rauhamaa <marko@pacujo.net> - 2016-03-31 17:02 +0300
Re: Suggestion: make sequence and map interfaces more similar Michael Selik <michael.selik@gmail.com> - 2016-04-01 04:19 -0400
Re: Suggestion: make sequence and map interfaces more similar Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-31 15:55 +0300
Re: Suggestion: make sequence and map interfaces more similar Marko Rauhamaa <marko@pacujo.net> - 2016-03-31 17:19 +0300
Re: Suggestion: make sequence and map interfaces more similar Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2016-03-31 15:08 +0200
Re: Suggestion: make sequence and map interfaces more similar Rustom Mody <rustompmody@gmail.com> - 2016-03-31 06:42 -0700
Re: Suggestion: make sequence and map interfaces more similar Chris Angelico <rosuav@gmail.com> - 2016-04-01 00:11 +1100
Re: Suggestion: make sequence and map interfaces more similar Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-31 14:17 +0100
Re: Suggestion: make sequence and map interfaces more similar Random832 <random832@fastmail.com> - 2016-03-31 09:27 -0400
Re: Suggestion: make sequence and map interfaces more similar Marko Rauhamaa <marko@pacujo.net> - 2016-03-31 17:13 +0300
Re: Suggestion: make sequence and map interfaces more similar Terry Reedy <tjreedy@udel.edu> - 2016-03-31 13:41 -0400
Re: Suggestion: make sequence and map interfaces more similar Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-31 15:12 +0100
Re: Suggestion: make sequence and map interfaces more similar Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2016-04-01 09:59 +0200
Re: Suggestion: make sequence and map interfaces more similar Tim Golden <mail@timgolden.me.uk> - 2016-04-01 09:27 +0100
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve@pearwood.info> - 2016-04-01 21:38 +1100
Re: Suggestion: make sequence and map interfaces more similar Marko Rauhamaa <marko@pacujo.net> - 2016-04-01 13:50 +0300
Re: Suggestion: make sequence and map interfaces more similar Rustom Mody <rustompmody@gmail.com> - 2016-04-01 07:41 -0700
Re: Suggestion: make sequence and map interfaces more similar Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-04-01 10:04 +0100
Re: Suggestion: make sequence and map interfaces more similar Marco Sulla <mail.python.org@marco.sulla.e4ward.com> - 2016-03-30 21:35 +0200
Re: Suggestion: make sequence and map interfaces more similar Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-30 21:31 +0100
Re: Suggestion: make sequence and map interfaces more similar Manolo Martínez <manolo@austrohungaro.com> - 2016-03-30 12:26 +0200
Re: Suggestion: make sequence and map interfaces more similar Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-30 13:40 +0300
Re: Suggestion: make sequence and map interfaces more similar Manolo Martínez <manolo@austrohungaro.com> - 2016-03-30 12:50 +0200
Re: Suggestion: make sequence and map interfaces more similar Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-30 14:21 +0300
Re: Suggestion: make sequence and map interfaces more similar Marko Rauhamaa <marko@pacujo.net> - 2016-03-30 14:44 +0300
Re: Suggestion: make sequence and map interfaces more similar Manolo Martínez <manolo@austrohungaro.com> - 2016-03-30 14:29 +0200
Re: Suggestion: make sequence and map interfaces more similar Marko Rauhamaa <marko@pacujo.net> - 2016-03-30 15:55 +0300
Re: Suggestion: make sequence and map interfaces more similar Manolo Martínez <manolo@austrohungaro.com> - 2016-03-30 15:13 +0200
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve@pearwood.info> - 2016-03-30 23:27 +1100
Re: Suggestion: make sequence and map interfaces more similar Marko Rauhamaa <marko@pacujo.net> - 2016-03-30 15:48 +0300
Re: Suggestion: make sequence and map interfaces more similar Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-30 17:38 +0300
Re: Suggestion: make sequence and map interfaces more similar Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-30 17:25 +0300
Re: Suggestion: make sequence and map interfaces more similar Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2016-03-30 10:55 +0200
Re: Suggestion: make sequence and map interfaces more similar Random832 <random832@fastmail.com> - 2016-03-30 08:50 -0400
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve@pearwood.info> - 2016-03-31 03:02 +1100
Re: Suggestion: make sequence and map interfaces more similar Random832 <random832@fastmail.com> - 2016-03-30 12:52 -0400
Re: Suggestion: make sequence and map interfaces more similar Steven D'Aprano <steve@pearwood.info> - 2016-03-31 13:44 +1100
Re: Suggestion: make sequence and map interfaces more similar Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2016-03-31 10:04 +0200
Re: Suggestion: make sequence and map interfaces more similar Marco Sulla <mail.python.org@marco.sulla.e4ward.com> - 2016-03-31 13:58 +0200
Re: Suggestion: make sequence and map interfaces more similar Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-31 13:30 +0100
Re: Suggestion: make sequence and map interfaces more similar Marco Sulla <mail.python.org@marco.sulla.e4ward.com> - 2016-03-31 14:49 +0200
Re: Suggestion: make sequence and map interfaces more similar Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-31 14:14 +0100
Re: Suggestion: make sequence and map interfaces more similar Marco Sulla <mail.python.org@marco.sulla.e4ward.com> - 2016-03-30 22:00 +0200
Re: Suggestion: make sequence and map interfaces more similar Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-30 21:36 +0100
Re: Suggestion: make sequence and map interfaces more similar Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-30 08:03 +0100
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