How to get inputs for a python program that run from another python program

[pradeep nair]

I would like to know how to pass keyboard input for a python script
which is ran by another script.

for eg:

hello1.py:

import os

if __name__=='__main__':

     print "I will call this other program called hello.py"
     os.system("python hello.py")
     print "hello1.py"


hello.py:

import os

if __name__=='__main__':

     print "press ENTER to display"
     #code wer if the user hits enter
     print "hello"
     #else the user hits any other keyboard button:
     sys.exit()


now wen i run hello1.py,i want the  some function or utility in
hello1.py that can pass the keyboard i/p  to hello.py .