Fixture for IPython.parallel and pytest

ipyparallel_test.py

import os
from pytest import yield_fixture


@yield_fixture(scope='module')
def ipy_client():

    def iptest_stdstreams_fileno():
        return os.open(os.devnull, os.O_WRONLY)

    # OMG-THIS-IS-UGLY-HACK: monkey-patch this global object to avoid
    # using the nose iptest extension (we're using pytest).
    # See https://github.com/ipython/ipython/blob/master/IPython/testing/iptest.py#L317-L319  # noqa
    from ipyparallel import Client
    import ipyparallel.tests
    ipyparallel.tests.nose.iptest_stdstreams_fileno = iptest_stdstreams_fileno

    # Start two engines engine (one is launched by setup()).
    ipyparallel.tests.setup()
    ipyparallel.tests.add_engines(1)
    yield Client(profile='iptest')
    ipyparallel.tests.teardown()


def test_client(ipy_client):
    print(ipy_client.ids)