import os dictionaryfile = "/root/john.txt" pgpencryptedfile = "helloworld.txt.gpg" array = open(dictionaryfile).readlines() for x in array: x = x.rstrip('\n') newstring = "echo " + x + " | gpg --passphrase-fd 0 " + pgpencryptedfile os.popen(newstring) I need to create something inside the for loop that will read gpg's output. When gpg outputs this string gpg: WARNING: message was not integrity protected, I need the loop to close and print Success! How can I do this, and what is the reasoning behind it? Thanks Everyone!