pytest-durations

library1.6.2pypypiunverified

pytest-durations is an active pytest plugin, currently at version 1.6.2, designed to report detailed execution times for both test functions and their associated fixtures. Unlike pytest's built-in `--durations` feature, it separates these timings and offers compatibility with distributed testing frameworks like pytest-xdist and time-traveling packages. The library sees frequent updates, with multiple minor and patch releases occurring throughout the year.

testing

pip install pytest-durations

github ↗package ↗

INSTALL

IMPORT

SIG · PYTEST-DURATIONS

pytest-durations

testingpythonv1.6.2

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

To use pytest-durations, simply install the plugin. It integrates automatically with pytest. Create a test file, then run pytest with the `--pytest-durations=N` option to show the N slowest durations. You can also specify `--pytest-durations-log=FILE` to output results to a file.

import pytest import time def test_fast_example(): time.sleep(0.01) assert True def test_slow_example_with_fixture(my_fixture): time.sleep(0.05) assert my_fixture == "setup_done" @pytest.fixture def my_fixture(): time.sleep(0.02) yield "setup_done" time.sleep(0.01) # To run: Save the above as test_durations.py and run 'pytest --pytest-durations=5' in the terminal.

pytest --version

Debug

Known issues

breakingPython 3.9 support was dropped in version 1.6.2. Python 3.8 support was dropped in version 1.5.0. Ensure your Python environment is 3.10 or newer (up to 3.14).

fix

Upgrade to Python 3.10 or a newer compatible version.

affects: >=1.5.0

breakingThe 'avg' column in duration reports was renamed to 'med' in version 1.6.0 to more accurately reflect median durations. Scripts or tools parsing the report output by column name will need updating.

fix

Update parsing logic to expect the 'med' column instead of 'avg'.

affects: >=1.6.0

deprecatedThe command-line option `--pytest-resultlog` was renamed to `--pytest-durations-log` in version 1.6.0 for consistency. While the old option might still work in some versions, it's considered deprecated.

fix

Update scripts to use `--pytest-durations-log` instead of `--pytest-resultlog`.

affects: >=1.6.0

gotchaIn version 1.5.2, the plugin switched from using `time.monotonic()` to `time.time()` to resolve a bug when used in conjunction with the `time-machine` library. If you rely on specific monotonic timing behavior or use `time-machine`, be aware of this change and test your setup accordingly.

fix

Review the impact of `time.time()` vs `time.monotonic()` on your specific use cases, especially with time-traveling libraries. Consider testing against affected versions.

affects: >=1.5.2

gotchaThe plugin's output differs from pytest's built-in `--durations` option. `pytest-durations` aims to provide separate metrics for fixture setup/teardown and test function execution, and supports xdist/time-traveling. Do not confuse the two outputs.

fix

Use `--pytest-durations` for the plugin's enhanced reporting, and be aware of the distinct information it provides compared to the native `--durations`.

affects: *

gotchaThe `--pytest-durations-group-by` option was introduced in 1.6.0 (improved in 1.6.1), allowing grouping by module, class, or function. The default is 'function'. Use `--pytest-durations-group-by=legacy` to revert to previous behavior if your parsing depends on it.

fix

Specify `--pytest-durations-group-by=legacy` if you need the old grouping behavior, or update your parsing logic to handle new grouping options.

affects: >=1.6.0

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'pytest_durations'

The pytest-durations plugin is not installed or is not available in the Python environment where pytest is being executed.

fix

Install the plugin in your active virtual environment: `pip install pytest-durations`.

pytest --durations does not show fixture timings

Users often confuse the built-in `pytest --durations=N` option (which lists N slowest tests) with the `pytest-durations` plugin, which provides detailed reports of all test and fixture durations using different CLI options.

fix

To get detailed test and fixture timings, use the plugin's specific options, for example: `pytest --durations-path durations_report.json`.

FileNotFoundError: [Errno 2] No such file or directory: 'some/nonexistent/path/report.json'

The directory specified in the `--durations-path` option for the report file does not exist, preventing the plugin from writing its output.

fix

Ensure the target directory for the report file exists before running pytest; for example: `mkdir -p some/nonexistent/path && pytest --durations-path some/nonexistent/path/report.json`.

pytest-durations file not generated

The pytest-durations plugin requires the `--durations-path` command-line argument to specify where to save the durations JSON file. Without it, no file will be created.

fix

Run pytest with the `--durations-path` option, e.g., `pytest --durations-path=durations.json`

ERROR: the 'pytest-durations' plugin requires pytest>=6.0.0

The installed pytest version is older than the minimum version required by the pytest-durations plugin.

fix

Upgrade your pytest installation to a compatible version: `pip install --upgrade pytest`

Upgrade

Version history

1.6.2latest on PyPI · released Mar 13, 2026

Audit

Dependencies

pytestrequiredCore testing framework that this plugin extends. Requires pytest>=4.6, with official support for pytest 7.0.0+.

time-machineoptionalExplicitly added for compatibility, especially related to duration measurements when 'time-traveling' is enabled.

pytest-xdistoptionalSupports serialization/deserialization for distributed testing scenarios.

Agent activity

41 hits · last 30 days

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Resources

githubhttps://github.com/blake-r/pytest-durations ↗

packagehttps://pypi.org/project/pytest-durations/ ↗