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Context manager support for contextvars.Context #99633
Description
Feature or enhancement
I would like to add __enter__ and __exit__ methods to contextvars.Context such that these two are mostly equivalent:
contextvars.copy_context().run(do_something_interesting)and:
with contextvars.copy_context():
do_something_interesting()Pitch
This makes it possible to combine Context enter/exit with other context managers:
import contextlib
import contextvars
@contextlib.contextmanager
def foo():
with contextvars.copy_context():
set_some_context_vars()
yieldMy personal motivating interest is controlling ContextVar values in pytest fixtures. For example:
import contextvars
import pytest
import module_under_test
@pytest.fixture
def clean_slate():
with contextvars.copy_context():
module_under_test._internal_state_context_var.set(None)
yield
def test_foo(clean_slate):
assert not module_under_test.is_initialized()Previous discussion
https://stackoverflow.com/q/59264158
Activity
pythongh-99633: Add context manager support to `contextvars.Context`
gvanrossum commentedon Nov 21, 2022
The idea should probably be reviewed by @1st1.
pythongh-99633: Add context manager support to `contextvars.Context`
pythongh-99633: Add context manager support to `contextvars.Context`
rhansen commentedon Feb 2, 2023
Friendly ping @1st1
apostolos-geyer commentedon May 26, 2024
+1
gvanrossum commentedon May 26, 2024
Maybe someone could contribute a PR?
pythongh-99633: Add context manager support to `contextvars.Context`
44 remaining items
pythongh-99633: Inline independent coroutine check
pythongh-99633: Add context manager support to `contextvars.Context`
pythongh-99633: _contextvars: Change private types to reduce casting
pythongh-99633: _contextvars: Clarify that the ref is stolen, not bor…
pythongh-99633: _contextvars: Enter the thread's initial context
pythongh-99633: _contextvars: Call non-tstate variants
pythongh-99633: New generator/coroutine `_context` property
pythongh-99633: Inline independent coroutine check
pythongh-99633: Add context manager support to `contextvars.Context`
pythongh-124872: Replace enter/exit events with "switched"
pythongh-124872: Replace enter/exit events with "switched"
gh-124872: Replace enter/exit events with "switched" (#124776)
pythongh-124872: Replace enter/exit events with "switched" (python#12…
gh-124872: Replace enter/exit events with "switched" (#125532)
pythongh-124872: Replace enter/exit events with "switched" (python#12…