pytest-benchmark 3.0.0

A ``py.test`` fixture for benchmarking code.

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A py.test fixture for benchmarking code. It will group the tests into rounds that are calibrated to the chosen timer. See calibration and FAQ.

• Free software: BSD license

Installation

pip install pytest-benchmark

Documentation

Available at: pytest-benchmark.readthedocs.org.

Examples

This plugin provides a benchmark fixture. This fixture is a callable object that will benchmark any function passed to it.

Example:

def something(duration=0.000001):
    """
    Function that needs some serious benchmarking.
    """
    time.sleep(duration)
    # You may return anything you want, like the result of a computation
    return 123

def test_my_stuff(benchmark):
    # benchmark something
    result = benchmark(something)

    # Extra code, to verify that the run completed correctly.
    # Sometimes you may want to check the result, fast functions
    # are no good if they return incorrect results :-)
    assert result == 123

You can also pass extra arguments:

def test_my_stuff(benchmark):
    benchmark(time.sleep, 0.02)

Or even keyword arguments:

def test_my_stuff(benchmark):
    benchmark(time.sleep, duration=0.02)

Another pattern seen in the wild, that is not recommended for micro-benchmarks (very fast code) but may be convenient:

def test_my_stuff(benchmark):
    @benchmark
    def something():  # unnecessary function call
        time.sleep(0.000001)

A better way is to just benchmark the final function:

def test_my_stuff(benchmark):
    benchmark(time.sleep, 0.000001)  # way more accurate results!

If you need to do fine control over how the benchmark is run (like a setup function, exact control of iterations and rounds) there’s a special mode - pedantic:

def my_special_setup():
    ...

def test_with_setup(benchmark):
    benchmark.pedantic(something, setup=my_special_setup, args=(1, 2, 3), kwargs={'foo': 'bar'}, iterations=10, rounds=100)

Screenshots

Normal run:

Compare mode (--benchmark-compare):

Histogram (--benchmark-histogram):

Also, it has nice tooltips.

Development

To run the all tests run:

tox

Credits

• Timing code and ideas taken from: https://bitbucket.org/haypo/misc/src/tip/python/benchmark.py

Changelog

3.0.0 (2015-08-11)

• Improved --help text for --benchmark-histogram, --benchmark-save and --benchmark-autosave.

• Benchmarks that raised exceptions during test now have special highlighting in result table (red background).

• Benchmarks that raised exceptions are not included in the saved data anymore (you can still get the old behavior back by implementing pytest_benchmark_generate_json in your conftest.py).

• The plugin will use pytest’s warning system for warnings. There are 2 categories: WBENCHMARK-C (compare mode issues) and WBENCHMARK-U (usage issues).

• The red warnings are only shown if --benchmark-verbose is used. They still will be always be shown in the pytest-warnings section.

• Using the benchmark fixture more than one time is disallowed (will raise exception).

• Not using the benchmark fixutre (but requiring it) will issue a warning (WBENCHMARK-U1).

3.0.0rc1 (2015-10-25)

• Changed --benchmark-warmup to take optional value and automatically activate on PyPy (default value is auto). MAY BE BACKWARDS INCOMPATIBLE

• Removed the version check in compare mode (previously there was a warning if current version is lower than what’s in the file).

3.0.0b3 (2015-10-22)

• Changed how comparison is displayed in the result table. Now previous runs are shown as normal runs and names get a special suffix indicating the origin. Eg: “test_foobar (NOW)” or “test_foobar (0123)”.

• Fixed sorting in the result table. Now rows are sorted by the sort column, and then by name.

• Show the plugin version in the header section.

• Moved the display of default options in the header section.

3.0.0b2 (2015-10-17)

• Add a --benchmark-disable option. It’s automatically activated when xdist is on

• When xdist is on or statistics can’t be imported then --benchmark-disable is automatically activated (instead of --benchmark-skip). BACKWARDS INCOMPATIBLE

• Replace the deprecated __multicall__ with the new hookwrapper system.

• Improved description for --benchmark-max-time.

3.0.0b1 (2015-10-13)

• Tests are sorted alphabetically in the results table.

• Failing to import statistics doesn’t create hard failures anymore. Benchmarks are automatically skipped if import failure occurs. This would happen on Python 3.2 (or earlier Python 3).

3.0.0a4 (2015-10-08)

• Changed how failures to get commit info are handled: now they are soft failures. Previously it made the whole test suite fail, just because you didn’t have git/hg installed.

3.0.0a3 (2015-10-02)

• Added progress indication when computing stats.

3.0.0a2 (2015-09-30)

• Fixed accidental output capturing caused by capturemanager misuse.

3.0.0a1 (2015-09-13)

• Added JSON report saving (the --benchmark-json command line arguments).

• Added benchmark data storage(the --benchmark-save and --benchmark-autosave command line arguments).

• Added comparison to previous runs (the --benchmark-compare command line argument).

• Added performance regression checks (the --benchmark-compare-fail command line argument).

• Added possibility to group by various parts of test name (the –benchmark-compare-group-by` command line argument).

• Added historical plotting (the --benchmark-histogram command line argument).

• Added option to fine tune the calibration (the --benchmark-calibration-precision command line argument and calibration_precision marker option).

• Changed benchmark_weave to no longer be a context manager. Cleanup is performed automatically. BACKWARDS INCOMPATIBLE

• Added benchmark.weave method (alternative to benchmark_weave fixture).

• Added new hooks to allow customization:

  • pytest_benchmark_generate_machine_info(config)

  • pytest_benchmark_update_machine_info(config, info)

  • pytest_benchmark_generate_commit_info(config)

  • pytest_benchmark_update_commit_info(config, info)

  • pytest_benchmark_group_stats(config, benchmarks, group_by)

  • pytest_benchmark_generate_json(config, benchmarks, include_data)

  • pytest_benchmark_update_json(config, benchmarks, output_json)

  • pytest_benchmark_compare_machine_info(config, benchmarksession, machine_info, compared_benchmark)

• Changed the timing code to:

  • Tracers are automatically disabled when running the test function (like coverage tracers).

  • Fixed an issue with calibration code getting stuck.

• Added pedantic mode via benchmark.pedantic(). This mode disables calibration and allows a setup function.

2.5.0 (2015-06-20)

• Improved test suite a bit (not using cram anymore).

• Improved help text on the --benchmark-warmup option.

• Made warmup_iterations available as a marker argument (eg: @pytest.mark.benchmark(warmup_iterations=1234)).

• Fixed --benchmark-verbose’s printouts to work properly with output capturing.

• Changed how warmup iterations are computed (now number of total iterations is used, instead of just the rounds).

• Fixed a bug where calibration would run forever.

• Disabled red/green coloring (it was kinda random) when there’s a single test in the results table.

2.4.1 (2015-03-16)

• Fix regression, plugin was raising ValueError: no option named 'dist' when xdist wasn’t installed.

2.4.0 (2015-03-12)

• Add a benchmark_weave experimental fixture.

• Fix internal failures when xdist plugin is active.

• Automatically disable benchmarks if xdist is active.

2.3.0 (2014-12-27)

• Moved the warmup in the calibration phase. Solves issues with benchmarking on PyPy.

  Added a --benchmark-warmup-iterations option to fine-tune that.

2.2.0 (2014-12-26)

• Make the default rounds smaller (so that variance is more accurate).

• Show the defaults in the --help section.

2.1.0 (2014-12-20)

• Simplify the calibration code so that the round is smaller.

• Add diagnostic output for calibration code (--benchmark-verbose).

2.0.0 (2014-12-19)

• Replace the context-manager based API with a simple callback interface. BACKWARDS INCOMPATIBLE

• Implement timer calibration for precise measurements.

1.0.0 (2014-12-15)

• Use a precise default timer for PyPy.

? (?)

• Readme and styling fixes (contributed by Marc Abramowitz)

• Lots of wild changes.