except* assumes that an exception group is truthy

[iritkatriel]

BPO	46219
Nosy	@vedgar, @brandtbucher, @iritkatriel
PRs	bpo-46219, 46221: simplify except* implementation following exc_info changes. Move helpers to exceptions.c. Do not assume that exception groups are truthy. #30289

^{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 2022-01-02.23:23:19.407>
created_at = <Date 2022-01-01.10:42:47.213>
labels = ['interpreter-core', 'type-bug', '3.11']
title = 'except* assumes that an exception group is truthy'
updated_at = <Date 2022-01-02.23:23:19.407>
user = 'https://github.com/iritkatriel'

bugs.python.org fields:

activity = <Date 2022-01-02.23:23:19.407>
actor = 'iritkatriel'
assignee = 'none'
closed = True
closed_date = <Date 2022-01-02.23:23:19.407>
closer = 'iritkatriel'
components = ['Interpreter Core']
creation = <Date 2022-01-01.10:42:47.213>
creator = 'iritkatriel'
dependencies = []
files = []
hgrepos = []
issue_num = 46219
keywords = ['patch']
message_count = 4.0
messages = ['409454', '409460', '409498', '409540']
nosy_count = 3.0
nosy_names = ['veky', 'brandtbucher', 'iritkatriel']
pr_nums = ['30289']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue46219'
versions = ['Python 3.11']

[iritkatriel]

except* checks truthiness of the output of PREP_RERAISE_STAR, and this gives the wrong result for false ExceptionGroup subclasses. See
#30302 (comment)

[iritkatriel]

... "for falsy ExceptionGroup subclasses"

[vedgar]

A long time ago, Python documentation used true and false as adjectives (as opposed to True and False, which are proper names for canonical true/false objects). I think it was BDFL's preference back then.

In the meantime, I suppose through JS's influence, Python documentation started to adopt ancient Perl terminology, where truhy and falsy were used as adjectives standing for what was previously known as true and false. I really don't like it, and I think English language is clear enough here (given the help of code font and capital letter) that we don't need to invent new words. Of course, it is up to the community to decide (and maybe the steering council might issue an opinion), but I'm telling you the history and my preference.

[iritkatriel]

New changeset 65e7c1f by Irit Katriel in branch 'main':
bpo-46219, 46221: simplify except* implementation following exc_info changes. Move helpers to exceptions.c. Do not assume that exception groups are truthy. (GH-30289)
65e7c1f