@lesteve Expect another PR once this is done. I'm here for addressing your reviews, if any 😄
CC: @aabadie @GaelVaroquaux

LGTM in general. There is an assert_less than you missed:

$ git grep 'assert_less'
joblib/test/test_hashing.py:def assert_less(a, b):
joblib/test/test_hashing.py:    assert_less(relative_diff, 0.3)
joblib/test/test_hashing.py:    assert_less(relative_diff, 0.3)

And some assert_equal or assert_not_equal that can still be removed I think

$ git grep -P 'assert_equal|assert_not_equal' | grep -v yield
joblib/test/test_disk.py:from joblib.testing import assert_equal, assert_raises
joblib/test/test_func_inspect.py:from joblib.testing import (assert_equal, assert_raises_regex, assert_raises)
joblib/test/test_hashing.py:from joblib.testing import (assert_equal, assert_not_equal,
joblib/test/test_memory.py:from joblib.testing import (assert_equal, assert_true, assert_false,
joblib/test/test_numpy_pickle.py:from joblib.testing import (assert_equal, assert_raises, assert_raises_regex,
joblib/test/test_numpy_pickle.py:                np.testing.assert_equal(result, expected)
joblib/test/test_numpy_pickle.py:                    np.testing.assert_equal(result, expected)
joblib/test/test_parallel.py:from joblib.testing import (assert_equal, assert_raises, check_subprocess_call,
joblib/test/test_parallel.py:    assert_equal(queue, [
joblib/test/test_parallel.py:    assert_equal(queue, [
joblib/test/test_parallel.py:    assert_equal(first_four,
joblib/testing.py:assert_equal = _dummy.assertEqual
joblib/testing.py:assert_not_equal = _dummy.assertNotEqual

I originally thought that bare assert would not play nice with nosetests (not sure why maybe it was the case at one point) but actually I tried and nosetests seem to support as well as the assert_ helpers maybe the error message is not as nice but I don't think we care that much as long as it does not take us too much time to transition to py.test.

All the assert_true and assert_false can go as well eventually.

I missed regex replacement of assert_less - thanks for pointing out. Also thanks for this terminal log. I am familiar with grep but this wonderful checking hack didn't strike me! I'll be using it henceforth 😄

You still have a few assert_* imports that you can remove without any harm i.e. things
from joblib.testing import assert_equal. Look at the git grep I posted above.

@lesteve I have left the assert_* used with yield statements untouched as I can yield an assert keyword and nose could execute it. That has to be done in phase 3 where parametrization of tests replaces yield based tests. Also, we cannot get rid of np.testing.assert_* at the moment as they deal with comparison of ndarrays specifically. e point me to some place if it is still missing from the ones I mentioned.

Meanwhile I would like to give an update - I have tested on both Travis and Appveyor - my fork has commits which have py.test command in Makefile, and both CIs are green 💚 😄

Once that comes in position, I will ⭐ pytestify ⭐ each module (already done two modules on my local git repo! I fear getting entangled so I am introducing small incremental changes on Github 😅

If we keep up the pace, this migration would be done before the year ends ! 🏁

@lesteve I have left the assert_* used with yield statements untouched as I can yield an assert keyword and nose could execute it.

Good point sorry I missed that.

I fear getting entangled so I am introducing small incremental changes on Github 😅

This is definitely the best way to get PR reviewed and merged quickly, thanks a lot for that!

If we keep up the pace, this migration would be done before the year ends ! 🏁

Sounds great!

I have pushed a small cosmetic change in your branch. I will merge once the CIs are green.

Merging, thanks a lot @karandesai-96!