unittest2 is a backport of the new features added to the unittest testing
framework in Python 2.7. It is tested to run on Python 2.4 - 2.7.
To use unittest2 instead of unittest simply replace ``import unittest`` with
unittest2 is maintained in a mercurial repository. The issue tracker is on
* `unittest2 hg <http://hg.python.org/unittest2>`_
* `unittest2 issue tracker
* `Article / Docs: New features in unittest
Thanks to Mark Roddy, there is also a version of for Python 2.3. This is
maintained as a separate branch and is a separate download.
To avoid problems with ``pip`` installing the wrong distribution, the Python 2.3
version of unittest2 can't be hosted on PyPI:
* `Download unittest2 0.5.1 for Python 2.3 <http://voidspace.org.uk/downloads/unittest2-0.5.1-python2.3.zip>`_
There is also a version of unittest2 for Python 3. This has the project name
"unittest2py3k" but uses the same package name ("unittest2"):
* `unittest2 for Python 3 <http://pypi.python.org/pypi/unittest2py3k>`_
Classes in unittest2 derive from the appropriate classes in unittest, so it
should be possible to use the unittest2 test running infrastructure without
having to switch all your tests to using unittest2 immediately. Similarly
you can use the new assert methods on ``unittest2.TestCase`` with the standard
unittest test running infrastructure. Not all of the new features in unittest2
will work with the standard unittest test loaders, runners result objects
New features include:
* ``addCleanups`` - better resource management
* *many* new assert methods including better defaults for comparing lists,
sets, dicts unicode strings etc and the ability to specify new default methods
for comparing specific types
* ``assertRaises`` as context manager, with access to the exception afterwards
* test discovery and new command line options (including failfast and better
handling of ctrl-C during test runs)
* class and module level fixtures: ``setUpClass``, ``tearDownClass``,
* test skipping and expected failures
* new ``delta`` keyword argument to ``assertAlmostEqual`` for more useful
comparison and for comparing non-numeric objects (like datetimes)
* ``load_tests`` protocol for loading tests from modules or packages
* ``startTestRun`` and ``stopTestRun`` methods on TestResult
* various other API improvements and fixes
.. note:: Command line usage
In Python 2.7 you invoke the unittest command line features (including test
discover) with ``python -m unittest <args>``. As unittest is a package, and
the ability to invoke packages with ``python -m ...`` is new in Python 2.7,
we can't do this for unittest2.
Instead unittest2 comes with a script ``unit2``.
`Command line usage
unit2 -v test_module
There is also a copy of this script called ``unit2.py``, useful for Windows
which uses file-extensions rather than shebang lines to determine what
program to execute files with. Both of these scripts are installed by
Until I write proper documentation, the best information on all the new features
is the development version of the Python documentation for Python 2.7:
Look for notes about features added or changed in Python 2.7.
unittest2 is already in use for development of `distutils2
Version 0.5.1 of unittest2 has feature parity with unittest_ in Python 2.7
final. If you want to ensure that your tests run identically under unittest2
and unittest in Python 2.7 you should use unittest2 0.5.1.
Later versions of unittest2 include changes in unittest made in Python 3.2
and onwards after the release of Python 2.7.
.. _unittest: http://docs.python.org/release/2.7/library/unittest.html
Differences between unittest2 and unittest in Python 2.7:
``assertItemsEqual`` does not silence Py3k warnings as this uses
``warnings.catch_warnings()`` which is new in Python 2.6 (and is used as a
context manager which would be a pain to make work with Python 2.4).
The underlying dictionary storing the type equality functions on TestCase is a
custom object rather than a real dictionary. This allows TestCase instances to
be deep-copyable on Python versions prior to 2.7.
``TestCase.longMessage`` defaults to True because it is better. It defaults to
False in Python 2.7 for backwards compatibility reasons.
``python -m package`` doesn't work in versions of Python before Python 2.7. The
command line features of unittest2 are provided by a ``unit2`` (and
``unit2.py``) script instead.
unittest2 includes a very basic setuptools compatible test collector. Specify
``test_suite = 'unittest2.collector'`` in your setup.py. This starts test
discovery with the default parameters from the directory containing setup.py, so
it is perhaps most useful as an example (see unittest2/collector.py).
A ``TestResult`` object with unexpected successes returns True
for ``result.wasSuccessful()``. Difficult to know if this is the correct
behaviour or not.
If a dotted path name is used for test discovery then a globally installed
module/package will still be used in preference of one in the current
directory. When doing discovery from a dotted path name we could check for this
The ``removeHandler`` decorator could also be a context manager.
`Issue 8313: <http://bugs.python.org/issue8313>`_, \<unprintable AssertionError object\>
message in unittest tracebacks, is hard to fix in versions of Python before 2.7.
The fix in Python 2.7 relies on changes to both the traceback module and
traceback objects. As the issue is rare I am leaving it unfixed in unittest2.
There are several places in unittest2 (and unittest) that call ``str(...)`` on
exceptions to get the exception message. This can fail if the exception was
created with non-ascii unicode. This is rare and I won't address it unless it is
actually reported as a problem for someone.
A comparison of text or long sequences (using ``assertSequenceEqual`` or
``assertMultiLineEqual`` etc) can take a *long* time to generate diffs for
failure messages. These methods use ``prettyprint`` and ``difflib``.
2010/07/12 - 0.5.1
Reverted script names created by setuptools back to "unit2" instead of
"unit2.py". (Not necessary as setuptools creates stub .exes for console scripts
2010/07/11 - 0.5.0
Addition of a setuptools compatible test collector (very basic). Specify
``test_suite = 'unittest2.collector'`` in your setup.py.
``TestSuite.debug()`` and ``TestCase.debug()`` now execute cleanup functions
and class and module level setups and teardowns.
No longer monkey-patch os.path.relpath for Python 2.4 / 2.5 so that projects
don't accidentally depend on our patching. Contributed by Konrad Delong.
Added a Python version specific unit2 entrypoint. This will, for example,
create a ``unit2-2.6`` script if unittest2 is installed with Python 2.6.
(Requires setuptools or distribute.)
Python 2.3 compatibility (in the python2.3 branch of the repository),
contributed by Mark Roddy.
setuptools console script entry points are created as '.py' scripts on Windows.
Feature parity with the Python 2.7 final release.
2010/06/06 - 0.4.2
Improved help message for ``unit2 discover -h``.
SkipTest in unittest.TestCase.setUpClass or setUpModule is now reported as a
skip rather than an error.
Excessively large diffs due to ``TestCase.assertSequenceEqual`` are no
longer included in failure reports. (Controlled by ``TestCase.maxDiff``.)
Matching files during test discovery is done in ``TestLoader._match_path``. This
method can be overriden in subclasses to, for example, match on the full file
path or use regular expressions for matching.
Addition of a setuptools compatible entrypoint for the unit2 test runner script.
Contributed by Chris Withers.
Tests fixed to be compatible with Python 2.7, where deprecation warnings are
silenced by default.
Feature parity with unittest in Python 2.7 RC 1.
2010/05/09 - 0.4.1
If test discovery imports a module from the wrong location (usually because the
module is globally installed and the user is expecting to run tests against a
development version in a different location) then discovery halts with an
``ImportError`` and the problem is reported.
Added docstrings to ``assertRegexpMatches`` and ``assertNotRegexpMatches``.
Putting functions in test suites no longer crashes.
Feature parity with unittest in Python 2.7 Beta 2.
2010/04/08 - 0.4.0
Addition of ``removeHandler`` for removing the control-C handler.
``delta`` keyword argument for ``assertAlmostEqual`` and
Addition of -b command line option (and ``TestResult.buffer``) for buffering
stdout / stderr during test runs.
Addition of ``TestCase.assertNotRegexpMatches``.
Allow test discovery using dotted module names instead of a path.
All imports requiring the signal module are now optional, for compatiblity
with IronPython (or other platforms without this module).
Tests fixed to be compatible with nosetest.
2010/03/26 - 0.3.0
``assertSameElements`` removed and ``assertItemsEqual`` added; assert that
sequences contain the same elements.
Addition of -f/--failfast command line option, stopping test run on first
failure or error.
Addition of -c/--catch command line option for better control-C handling during
Added ``BaseTestSuite``, for use by frameworks that don't want to support shared
class and module fixtures.
Skipped test methods no longer have ``setUp`` and ``tearDown`` called around
Faulty ``load_tests`` functions no longer halt test discovery.
Using non-strings for failure messages now works.
Potential for ``UnicodeDecodeError`` whilst creating failure messages fixed.
Split out monolithic test module into a package.
BUGFIX: Correct usage message now shown for unit2 scripts.
BUGFIX: ``__unittest`` in module globals trims frames from that module in
2010/03/06 - 0.2.0
The ``TextTestRunner`` is now compatible with old result objects and standard
(non-TextTestResult) ``TestResult`` objects.
``setUpClass`` / ``tearDownClass`` / ``setUpModule`` / ``tearDownModule`` added.
2010/02/22 - 0.1.6
Fix for compatibility with old ``TestResult`` objects. New tests can now be run
with nosetests (with a DeprecationWarning for ``TestResult`` objects without
methods to support skipping etc).
* Document ``SkipTest``, ``BaseTestSuite```