How to set self.maxDiff in nose to get full diff output?

Question

When using nose 1.2.1 with Python 3.3.0, I sometimes get an error message similar to the following one

======================================================         


        

Answer 1

In python 2.7.3, nose 1.3.0, doing the following is working for me:

assert_equal.im_class.maxDiff = None
assert_equal(huge_thing, other_huge_thing)

Answer 2

Here you have it (what google told me):

# http://pdf2djvu.googlecode.com/hg/tests/common.py
try:
    from nose.tools import assert_multi_line_equal
except ImportError:
    assert_multi_line_equal = assert_equal
else:
    assert_multi_line_equal.im_class.maxDiff = None

Answer 3

This works in python 2.7:

    from unittest import TestCase
    TestCase.maxDiff = None

It'll set the default maxDiff for all TestCase instances, including the one that assert_equals and friends are attached to.

Answer 4

I had the same problem in Python 3 (from reading the other answers here) and using im_class did not work. The snippet below works in Python 3 (cf. How to find instance of a bound method in Python?):

assert_equal.__self__.maxDiff = None

As @Louis commented, the convenience functions are bound methods on a Dummy instance. They all seem to be on the same instance, so changing this for e.g. assert_equal will change it for assert_dict_equal et cetera. From the Python docs, __self__ is available from Python 2.6 and forward.

Answer 5

I recently ran into this problem .... I was forcing a MS type line ending ....

MSstr="""hi\r
there\r"""
expected="""hi
there"""

self.assertEqual(MSsrt, expected) 

That crashed with the horrible errors other are using.

In PyCharm it said the files were identical !!

I removed the \r - no more crash and tests now pass.

Hope that saves someone the 2 hours it cost me.

Answer 6

You set maxDiff to None.

But you will have to actually use a unittest.TestCase for your tests for that to work. This should work.

class MyTest(unittest.TestCase):

    maxDiff = None

    def test_diff(self):
          <your test here>