how to make a python file run without py extension

I had a small python script that takes input from the command line arguments and done some operations using the inputs taken and display the result

Below is the working example code

some_file.py

import sys

arguments = sys.argv
first_name  = sys.argv[1]
second_name = sys.argv[2]

print "Hello {0} {1} !!!!".format(first_name,second_name)

Now i am executing this as

python some_file.py Steve jobs

Result :

Hello Steve Jobs !!!!

Now what all i want is, i don't want to use python command before file name and extension of python file name, that is i want to run the file as a command tool as below

some_file  Steve Jobs

so what to do in order to run the python file as above ?