nose2's extends unittest to make testing nicer.

nose2 originated as the successor to nose.

nose2 is a distinct project and does not support all of the behaviors of nose. See differences for a thorough rundown.

pytest is an excellent test framework and we encourage users to consider it for new projects.

It has a bigger team of maintainers and a larger community of users.

Because nose2 is based on unittest, you can start from the Python Standard Library's documentation for unittest and then use nose2 to add value on top of that.

nose2 looks for tests in Python files whose names start with test and runs every test function it discovers.

Here's an example of a simple test, written in typical unittest style:

# in test_simple.py
import unittest

class TestStrings(unittest.TestCase):
    def test_upper(self):
        self.assertEqual("spam".upper(), "SPAM")

You can then run this test like so:

$ nose2 -v
test_upper (test_simple.TestStrings) ... ok

----------------------------------------------------------------------
Ran 1 test in 0.000s

OK

However, nose2 supports more testing configuration and provides more tools than unittest on its own.

For example, this test exercises just a few of nose2's features:

# in test_fancy.py
from nose2.tools import params

@params("Sir Bedevere", "Miss Islington", "Duck")
def test_is_knight(value):
    assert value.startswith('Sir')

and then run this like so:

$ nose2 -v --pretty-assert
test_fancy.test_is_knight:1
'Sir Bedevere' ... ok
test_fancy.test_is_knight:2
'Miss Islington' ... FAIL
test_fancy.test_is_knight:3
'Duck' ... FAIL

======================================================================
FAIL: test_fancy.test_is_knight:2
'Miss Islington'
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/mnt/ebs/home/sirosen/tmp/test_fancy.py", line 6, in test_is_knight
    assert value.startswith('Sir')
AssertionError

>>> assert value.startswith('Sir')

values:
    value = 'Miss Islington'
    value.startswith = <built-in method startswith of str object at 0x7f3c3172f430>
======================================================================
FAIL: test_fancy.test_is_knight:3
'Duck'
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/mnt/ebs/home/sirosen/tmp/test_fancy.py", line 6, in test_is_knight
    assert value.startswith('Sir')
AssertionError

>>> assert value.startswith('Sir')

values:
    value = 'Duck'
    value.startswith = <built-in method startswith of str object at 0x7f3c3172d490>
----------------------------------------------------------------------
Ran 3 tests in 0.001s

FAILED (failures=2)

Full documentation for nose2 is available at docs.nose2.io

nose2 versions are numbered 0.MAJOR.MINOR. Minor releases contain bugfixes or smaller features. Major features or backwards incompatible changes are done in major releases.

For a full description of all past versions and changes, see the changelog.

nose2 requires Python 3.

It supports all versions currently supported by the CPython team, and also aims to support PyPy and cpython betas.

Python 2 is no longer supported. The 0.12.x line of releases contains the last versions which supported Python 2.

Users of Python 2 should understand that Python 2 is EOL and the Python 2 support line for nose2 is similarly considered EOL.

If you want to make contributions, please read the contributing guide.