Pexpect and a Linux Terminal

[asgarde at msn.com]

hello,

I'm new in Python and i would like to use Pexpect to execute a root
command (i want to mount via a Pyhton script a drive)

so that's my script for the moment :

from os import *
import pexpect
import os
cmd1="su -"
cmd2="mount -o loop /home/user/my.iso /mnt/disk"
pwd="mypassword"

child = pexpect.spawn(cmd1)
child.sendline('Mot de passe :')
child.sendline(pwd+"\r\n")
child.sendline(cmd2)

(is a French Terminal so 'Mot de passe' means Password :'

After that i try to execute it, and nothing happened, i know how to
lunch py file via python but i supposed the script don't detect the
prompt Password.

if anyone can help me please :)

Have a nice day !