Registry / testing / pytest-run-parallel

pytest-run-parallel

library0.9.1pypypiunverified

A pytest plugin to run tests concurrently using threads. It automatically detects thread-unsafe tests (e.g., using fixtures like tmp_path, monkeypatch, capsys, or mocking) and marks them as serial. Version 0.8.2 supports Python >=3.9. Releases are intermittent.

testing

pip install pytest-run-parallel

github ↗package ↗

INSTALL

IMPORT

SIG · PYTEST-RUN-PARALLE

pytest-run-parallel

testingpythonv0.9.1

Install

2.8s avg

Import

—

Disk

29MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.9.1 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

installs and imports cleanly · install 0.0s · import 0.000s · 30.8MB

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 2.8s · import 0.000s · 31MB

29MB installed

● package 29MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

pytest_run_parallel

✓ pytest_plugins = ['pytest_run_parallel']

✗ import pytest_run_parallel

This is a pytest plugin; it's auto-discovered when installed. No explicit import needed in conftest.

Run pytest with parallel threads. The plugin automatically parallelizes tests unless they are detected as thread-unsafe.

# In your project root, run: pytest --parallel-threads=auto # Or set a fixed number: pytest --parallel-threads=4 # To detect thread-unsafe tests (default on): pytest --parallel-threads=auto --detect-thread-unsafe

Debug

Known issues

gotchaThe plugin automatically detects thread-unsafe patterns (fixtures like tmp_path, monkeypatch, capsys, etc.). If your test uses these, it will run serially, even with --parallel-threads. No explicit mark needed.

fix

To force parallelism on a test that uses thread-unsafe fixtures, mark it with @pytest.mark.parallel. However, this may cause flaky tests.

affects: >=0.4.0

breakingIn v0.8.0, the --parallel-threads-limit mark was added. Before that, you could only set global parallelism. Also, gc.collect detection was added in v0.8.0, marking tests using gc.collect as thread-unsafe.

fix

If you rely on gc.collect in tests, they will now run serially unless you use --disable-thread-unsafe-detection or mark them as parallel.

affects: >=0.8.0

deprecatedThe --forever flag interaction with pytest-xdist changed in v0.7.1. The flag may not work as expected when used with xdist.

fix

Avoid using --forever with pytest-xdist. Use --parallel-threads instead for parallel execution.

affects: >=0.7.1

gotchaTests that use unittest.mock or fixtures like monkeypatch are automatically detected as thread-unsafe and run serially. This includes MagicMock, patch, etc.

fix

If you know your mock usage is safe, you can disable detection with --disable-thread-unsafe-detection, but be careful about race conditions.

affects: >=0.4.3

Upgrade

Version history

0.9.1latest on PyPI · released Jun 3, 2026

Audit

Dependencies

No dependency data recorded yet.

Agent activity

10 hits · last 30 days

node

Resources

githubhttps://github.com/Quansight-Labs/pytest-run-parallel ↗

packagehttps://pypi.org/project/pytest-run-parallel/ ↗