pytest-loop

What it is and what it does

pytest-loop is a pytest plugin that lets you run the same test or test suite repeatedly—either a fixed number of times or for a specified duration (hours, minutes, seconds). It's designed to help diagnose intermittent test failures by running tests many times in succession, and to perform stress testing by running tests continuously over a time window.

The plugin integrates with pytest's command-line interface and decorator system. You can specify repetition via `--loop=N` on the command line, or mark individual tests with `@pytest.mark.loop(N)`. For time-based looping, you use `--hours`, `--minutes`, and `--seconds` options, optionally with a `--delay` between iterations. It merges functionality from pytest-repeat and pytest-stress, and works with standard pytest test functions but not with unittest.TestCase classes.

Use it for:

• Run a flaky test 1000 times with `-x` to stop at first failure and capture the failure condition.
• Stress-test a test suite for 8 hours to detect resource leaks or timing-dependent bugs.
• Mark a specific test with `@pytest.mark.loop(5)` to repeat only that test without modifying the command line.
• Diagnose race conditions by looping concurrent or async tests for an extended duration.
• Verify test stability before merging by running the full suite repeatedly for a fixed time window.

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

A pytest plugin that repeats tests a fixed number of times or for a specified duration, useful for detecting intermittent failures and stress-testing.

Yes. The plugin is actively maintained, has no known vulnerabilities, and solves a real problem—detecting intermittent failures and stress-testing. Low install friction (one dependency, pure Python), broad Python version support, and Production/Stable status make it a safe choice for projects that need to diagnose flaky tests or validate stability under repeated execution.

Install

pytest-loop on PyPI

pip install pytest-loop

uv add pytest-loop

poetry add pytest-loop

Installing pytest-loop

Before you install

Low friction: pure Python wheel with only pytest as a runtime dependency. Actively maintained with recent commits and marked Production/Stable.

License in practice

Licensed under Mozilla Public License 2.0 (copyleft). You must disclose source modifications and distribute under the same license if you modify and redistribute the package; using it unmodified as a dependency carries minimal obligation.

Quickstart

pip install pytest-loop

pytest --loop=10 test_file.py

# Or with decorator:
import pytest

@pytest.mark.loop(3)
def test_example():
    pass

Requires Python 3.7+ and pytest 7 or newer. Does not work with unittest.TestCase test classes.

Verify before relying

• Whether the package handles test collection and result aggregation correctly across all pytest versions in the 7+ range.
• Performance impact of looping on large test suites or when combined with other pytest plugins.

Package facts

Evidence: pytest_loop-1.0.13-py3-none-any.whl

Keywords: duration, loop, pytest, pytest-loop, pytest-repeat, pytest-rerun, pytest-stress, repeat, rerun, stress, test, time

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