1from mpi4py import MPI 2import numpy 3 4comm = MPI.COMM_WORLD 5rank = comm.Get_rank() 6 7# passing MPI datatypes explicitly 8if rank == 0: 9 data = numpy.arange(1000, dtype='i') 10 comm.Send([data, MPI.INT], dest=1, tag=77) 11elif rank == 1: 12 data = numpy.empty(1000, dtype='i') 13 comm.Recv([data, MPI.INT], source=0, tag=77) 14 15# automatic MPI datatype discovery 16if rank == 0: 17 data = numpy.arange(100, dtype=numpy.float64) 18 comm.Send(data, dest=1, tag=13) 19elif rank == 1: 20 data = numpy.empty(100, dtype=numpy.float64) 21 comm.Recv(data, source=0, tag=13) 22