Following call returns only in stdout:
>>> process = subprocess.Popen(['ls','-l'])
>>> total 132
-rw-r--r-- 1 bernd bernd 0 2010-10-06 10:03 abc
-rw-r--r-- 1 bernd bernd 0 2010-10-06 10:04 abcd
-rw-r--r-- 1 bernd bernd 660 2010-09-30 21:34 curses.py
this way you can handle the output in Python:
>>> process = subprocess.Popen(['ls','-l'], stdout=subprocess.PIPE)
>>> print process.stdout.read()
total 132
-rw-r--r-- 1 bernd bernd 0 2010-10-06 10:03 abc
-rw-r--r-- 1 bernd bernd 0 2010-10-06 10:04 abcd
-rw-r--r-- 1 bernd bernd 660 2010-09-30 21:34 curses.py