small edits

docs.it4i/anselm/software/mpi/mpi4py-mpi-for-python.md

@@ -145,6 +145,7 @@ else:
     total = None
 
 comm.Barrier()
+#collect the partial results to total sum
 comm.Reduce(summ, total, op=MPI.SUM, root=0)
 
 stop_time = time.time()
@@ -158,9 +159,9 @@ if rank == 0:
     print ("-----", int((time.time()-start_time)*1000), "-----")
 ```
 
-Execute the code above like:
+Execute the code above as:
 ```console
-$ qsub -I -q qexp -l select=4:ncpus=16,walltime=00:30:00 -A DD-13-5
+$ qsub -I -q qexp -l select=4:ncpus=16,walltime=00:30:00
 
 $ ml Python/3.5.2-intel-2017.00