from mpi4py import MPI import horovod.tensorflow as hvd # Split COMM_WORLD into subcommunicators subcomm = MPI.COMM_WORLD.Split(color=MPI.COMM_WORLD.rank % 2, key=MPI.COMM_WORLD.rank) # Initialize Horovod hvd.init(comm=subcomm) print('COMM_WORLD rank: %d, Horovod rank: %d' % (MPI....