Check if Python User is Root

How to check if the user calling a python script is running as root.

import os

if os.geteuid()==0:
  print "Running as root."
else:
  print "User is not root."

The following script will exit with a message to the user if they are not root.

#! /usr/bin/env python
import os, sys

# This script must be run as root!
if not os.geteuid()==0:
    sys.exit('This script must be run as root!')