how to interact with an external script(program)

Question

there is a script that expects keyboard input, i can call that script with os.system('./script') in python,

how is it possible to send back an input to the script from another calling script?

update:

the script is:

$ cat script
#!/usr/bin/python
for i in range(4):
        name=raw_input('enter your name')
        print 'Welcome %s :) ' % name

when i try without a for loop, it works but it shows the output only when the script quits.

>>> p = subprocess.Popen('./script',stdin=subprocess.PIPE)
>>> p.communicate('navras')
enter your nameWelcome navras :)

when i try it with the foor loop, it throws error, How to display the statements interactive as and when the stdout is updated with new print statements

>>> p.communicate('megna')
enter your nameWelcome megna :)
enter your nameTraceback (most recent call last):
  File "./script", line 3, in <module>
    name=raw_input('enter your name')
EOFError: EOF when reading a line
(None, None)

Answer 1

You can use subprocess instead of os.system:

p = subprocess.Popen('./script',stdin=subprocess.PIPE)
p.communicate('command')

its not testet

Answer 2

In fact, os.system and os.popen are now deprecated and subprocess is the recommended way to handle all sub process interaction.