I am using Fedora 17 xfce and I am programming in Python 2.7.3. Fedora uses a package manager called yum. I have a python script that searches for packages like this: import os package = raw_input("Enter package name to search: ") os.system("yum list " + package) So I want python to check if in the output of this command exists the words "No matching packages to list". I checked a similar question and I tried some methods [http://stackoverflow.com/questions/2502833/python-store-output-of-subprocess-call-in-a-string][1] but the string contained only the first line of the output. Thanks in advance