Enum docs claim replacing __new__ is not possible

[ethanfurman]

BPO	21738
Nosy	@ezio-melotti, @ethanfurman
Files	issue21738.stoneleaf.01.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = <Date 2014-09-17.02:15:54.484>
created_at = <Date 2014-06-12.18:35:45.431>
labels = ['type-feature', 'docs']
title = 'Enum docs claim replacing __new__ is not possible'
updated_at = <Date 2014-09-17.02:15:54.450>
user = 'https://github.com/ethanfurman'

bugs.python.org fields:

activity = <Date 2014-09-17.02:15:54.450>
actor = 'ethan.furman'
assignee = 'docs@python'
closed = True
closed_date = <Date 2014-09-17.02:15:54.484>
closer = 'ethan.furman'
components = ['Documentation']
creation = <Date 2014-06-12.18:35:45.431>
creator = 'ethan.furman'
dependencies = []
files = ['35699']
hgrepos = []
issue_num = 21738
keywords = ['patch']
message_count = 4.0
messages = ['220372', '221037', '221052', '226974']
nosy_count = 4.0
nosy_names = ['ezio.melotti', 'docs@python', 'ethan.furman', 'python-dev']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue21738'
versions = ['Python 3.4', 'Python 3.5']

[ethanfurman]

Replacing __new__ in an Enum subclass is not possible /in the subclass definition/, but is easily replaced via monkey-patching after the class has been defined.

Docs need to be updated to reflect this.

[ezio-melotti]

Is this common enough that it deserves to be documented?

[ethanfurman]

Common, no. And if the docs were silent on the matter that would be okay, but unfortunately the docs declare that it is not possible, which is just plain wrong.

Patch also mentions _value_ as that is the supported interface when customizing __new__ methods.

[python-dev]

New changeset 28c21f09719e by Ethan Furman in branch '3.4':
bpo-21738: clarify usage of __new__ in Enum subclasses
https://hg.python.org/cpython/rev/28c21f09719e

New changeset 91ec34801232 by Ethan Furman in branch 'default':
bpo-21738: clarify usage of __new__ in Enum subclasses
https://hg.python.org/cpython/rev/91ec34801232