pytest-easyMPI 0.0.1

Short example

The following shows an example of how to combine a serial and a parallel test in a single test file. The parallel test is run using 4 MPI ranks:

from pytest_easyMPI import mpi_parallel

def test_serial():
    assert True

@mpi_parallel(4)
def test_parallel():
    # Import MPI only inside the test that needs it
    # (to avoid spawning too many MPI communicators)
    from mpi4py import MPI

    data = MPI.COMM_WORLD.gather(MPI.COMM_WORLD.Get_rank())
    if MPI.COMM_WORLD.Get_rank() == 0:
        assert sum(range(MPI.COMM_WORLD.Get_size())) == sum(data)

The test can then be run by calling:

pytest