from mpi4py import MPI from array import array from math import pi as PI from sys import argv cmd = 'cpi-worker-py.exe' if len(argv) > 1: cmd = argv[1] print("%s -> %s" % (argv[0], cmd)) worker = MPI.COMM_SELF.Spawn(cmd, None, 5) n = array('i', [100]) worker.Bcast([n,MPI.INT], root=MPI.ROOT) pi = array('d', [0.0]) worker.Reduce(sendbuf=None, recvbuf=[pi, MPI.DOUBLE], op=MPI.SUM, root=MPI.ROOT) pi = pi[0] worker.Disconnect() print('pi: %.16f, error: %.16f' % (pi, abs(PI-pi)))