Support operator module callables in inspect.signature

[plammens]

BPO	42785
Nosy	@plammens

^{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 = None
created_at = <Date 2020-12-30.12:38:08.138>
labels = ['type-feature', 'library', '3.9']
title = 'Support operator module callables in inspect.signature'
updated_at = <Date 2020-12-30.12:39:03.612>
user = 'https://github.com/plammens'

bugs.python.org fields:

activity = <Date 2020-12-30.12:39:03.612>
actor = 'plammens'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2020-12-30.12:38:08.138>
creator = 'plammens'
dependencies = []
files = []
hgrepos = []
issue_num = 42785
keywords = []
message_count = 2.0
messages = ['384061', '384062']
nosy_count = 1.0
nosy_names = ['plammens']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue42785'
versions = ['Python 3.9']

[plammens]

Currently, inspect.signature doesn't support all callables from the operator module, e.g. operator.attrgetter:

>>> import inspect
>>> import operator
>>> inspect.signature(operator.attrgetter("spam"))
ValueError: callable operator.attrgetter('is_host') is not supported by signature

Support for this could be added either directly to inspect.signature or by adding __signature__ attributes to operator's classes.

[plammens]

Correction:

ValueError: callable operator.attrgetter('spam') is not supported by signature

[wRAR]

Looks like this is fixed in Python 3.12:

>>> import inspect
>>> import operator
>>> inspect.signature(operator.attrgetter("spam"))
<Signature (*args, **kwargs)>

[wRAR]

Specifically, it's fixed in the unreleased 3.12.3 (currently available in Debian unstable), probably by #116198