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Documented uvloop pattern is deprecated #1346
Description
Currently, the documentation suggests
import pytest
import uvloop
@pytest.fixture(scope="session")
def event_loop_policy():
return uvloop.EventLoopPolicy()EventLoopPolicy was deprecated in MagicStack/uvloop#638.
Activity
seifertm commentedon Jan 28, 2026
That makes sense. The policy system is also deprecated as of Python 3.14.
pytest-asyncio doesn't really have a replacement yet. We want to keep the possibility to test with different loops, but didn't really find a suitable API for this so far. There's a draft PR that introduces a loop_factory argument to the asyncio marker, but it has some limitations.
tjkuson commentedon Jan 28, 2026
I assume you meant to link to #1164?
Thanks for explaining, I'll read the thread and see if I have ideas when I next have some free time...
[-]Documented `uvloop` pattern is depcreated[/-][+]Documented `uvloop` pattern is deprecated[/+]Docs: update uvloop how-to to avoid deprecated EventLoopPolicy
ivanthewebber commentedon Mar 9, 2026
The text and the example in that documentation also doesn't match. I for one would appreciate it if that documentation could be improved in the meantime
golikovichev commentedon May 21, 2026
+1 on ivanthewebber's note about the text/example mismatch. As a downstream user adopting pytest-asyncio for new projects, the current snippet is misleading on two fronts:
uvloop.EventLoopPolicy()is deprecated since uvloop 0.21 (per Fix build for Python 3.14 MagicStack/uvloop#638) - calling it in the fixture emits aDeprecationWarningeven before the test runs.event_loop_policywill age fast.Two minimal interim options for the docs page (not blocking the long-term #1164 work):
a) Replace the snippet with the
asyncio.Runner(loop_factory=uvloop.new_event_loop)pattern (works today, sidesteps deprecation, but requires the user to wire it through pytest-asyncio).b) Keep the existing snippet but add a one-line callout noting both deprecations and pointing at #1164 for the future API direction.
Happy to PR option (b) - one-paragraph callout, no API contract change - if maintainers prefer that as a holding pattern.
tjkuson commentedon May 21, 2026
For what it's worth, this should be resolved once 1.4.0 is released (pre-releases are available if you'd like to try it out early).
golikovichev commentedon May 21, 2026
Thanks for the heads-up. Will try v1.4.0a2 to confirm the new pattern. Dropping the interim docs callout offer since the structural fix is on its way.
seifertm commentedon May 26, 2026
#1373 improves the documentation by mentioning the deprecation of the policy system and providing a non-deprecated approach in the how-to. I'd say this issue is sufficiently addressed.