concurrencytest

Python testtools extension for running unittest test suites concurrently.

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• Development: GitHub
• Download/Install: PyPI
• License: GPLv2+
• Copyright (c) 2013-2026 Corey Goldberg
• Original code from:
  • Bazaar (bzrlib.tests.__init__.py, v2.6, copied Jun 01 2013)
  • Copyright (c) 2005-2011 Canonical Ltd

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Install from PyPI:

pip install concurrencytest

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Requires:

• support for os.fork() (Unix-like systems only)
• testtools : pip install testtools
• python-subunit : pip install python-subunit

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Example:

import time
import unittest

from concurrencytest import ConcurrentTestSuite, fork_for_tests


class ExampleTestCase(unittest.TestCase):
    """Dummy tests that sleep for demo."""

    def test_me_1(self):
        time.sleep(0.5)

    def test_me_2(self):
        time.sleep(0.5)

    def test_me_3(self):
        time.sleep(0.5)

    def test_me_4(self):
        time.sleep(0.5)


runner = unittest.TextTestRunner()

# Run the tests from above sequentially
suite = unittest.TestLoader().loadTestsFromTestCase(ExampleTestCase)
runner.run(suite)

# Run same tests concurrently across 4 processes
suite = unittest.TestLoader().loadTestsFromTestCase(ExampleTestCase)
concurrent_suite = ConcurrentTestSuite(suite, fork_for_tests(4))
runner.run(concurrent_suite)

# Run same tests concurrently using 1 process per available CPU core
suite = unittest.TestLoader().loadTestsFromTestCase(ExampleTestCase)
concurrent_suite = ConcurrentTestSuite(suite, fork_for_tests())
runner.run(concurrent_suite)

Output:

.....
----------------------------------------------------------------------
Ran 4 tests in 2.002s

OK
....
----------------------------------------------------------------------
Ran 4 tests in 0.510s

OK
....
----------------------------------------------------------------------
Ran 4 tests in 0.507s

OK