Should warnings.warn default to stacklevel=2?

[asottile]

BPO	44296
Nosy	@asottile

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

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GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2021-06-02.23:55:20.255>
labels = ['type-bug', 'library', '3.11']
title = 'Should warnings.warn default to stacklevel=2?'
updated_at = <Date 2021-06-02.23:55:20.255>
user = 'https://github.com/asottile'

bugs.python.org fields:

activity = <Date 2021-06-02.23:55:20.255>
actor = 'Anthony Sottile'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2021-06-02.23:55:20.255>
creator = 'Anthony Sottile'
dependencies = []
files = []
hgrepos = []
issue_num = 44296
keywords = []
message_count = 1.0
messages = ['394960']
nosy_count = 1.0
nosy_names = ['Anthony Sottile']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue44296'
versions = ['Python 3.11']

[asottile]

I have yet to come across a usecase where stacklevel=1 makes sense -- usually it is more helpful to point at the calling code than the function which is itself warning

my proposal is to update the default for stacklevel= from 1 to 2

an example bpo where this is relevant is bpo-44295

[gpshead]

stacklevel is also often not a great API as it's an integer that depends on a pile of calling code far from the warnings.warn call itself. #39615 is likely to provide a more useful API. check the module/file of the stack frame and bubble up outside of the current file/module/package or a set of such.