[New-bugs-announce] [issue24254] Make class definition namespace ordered by default

[Eric Snow]

New submission from Eric Snow:

Here's a work-in-progress patch that uses OrderedDict as the default class definition namespace (instead of dict).  While the actual class namespace is a dict, the definition order is preserved on a new attribute on class objects: __definition_order__.  This is useful for cases such as class decorators that would make use of the definition order to post-process the class.  This is something that Guido okay'ed a while back.

It may be a stretch to get this into 3.5, but the final change should be pretty small.  It also depends on the C implementation of OrderedDict (see issue #16991) which has not landed and may not make it in time.

Note that the patch is still a bit buggy, partly due to bugs in the C OrderedDict patch.  Also, the attached patch is based off the C OrderedDict patch, so I expect reitveld won't be able to handle it.  The code on which the patch is based may be found in the "class-namespace" branch of https://pypi.python.org/pypi/cyordereddict.

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assignee: eric.snow
components: Interpreter Core
files: odict-class-definition-namespace.diff
keywords: patch
messages: 243729
nosy: eric.snow, ncoghlan
priority: normal
severity: normal
status: open
title: Make class definition namespace ordered by default
type: behavior
versions: Python 3.5
Added file: http://bugs.python.org/file39446/odict-class-definition-namespace.diff

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<http://bugs.python.org/issue24254>
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