code: def master(icomm):
      n = get_n()
      wt = MPI.Wtime()
      n = N.array(n, "i")
      icomm.Send([n, MPI.INT], dest=0)
      pi = N.array(0, "d")
      icomm.Recv([pi, MPI.DOUBLE], source=0)
      wt = MPI.Wtime() - wt
      if n == 0:
          return
      np = icomm.Get_remote_size()
      view(pi, np, wt)
  
file_path: mpi4py/demo/compute-pi/cpi-dpm.py
imports: import sys
  from mpi4py import MPI
  import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: master(icomm) without return types