How to install MPI

Follow the below instructions to install Mpi4py on Ubuntu 14.04.1

Login as root user or do --> sudo su -
And now execute below commands

apt-get update
apt-get install build-essential 
apt-get install openmpi-bin openmpi-checkpoint openmpi-common openmpi-doc libopenmpi-dev
sudo apt-get install python-pip
sudo apt-get install python-dev
sudo pip install mpi4py

To check whether MPI is installed or not
Copy below program and name the file as hello.py

#hello.py
from mpi4py import MPI
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
print "hello world from process ", rank

To run the program --> mpiexec -n 5 python  hello.py
Output will be as mentioned below (Number sequence may vary)

hello world from process 0
hello world from process 1
hello world from process 3
hello world from process 2
hello world from process 4

For more MPI tutorials --> http://materials.jeremybejarano.com/MPIwithPython/introMPI.html