I'm using Python 2.6. After checking the following link: Running shell command from Python and capturing the output Here is the code I plan to do:
    import subprocess
    # input: user email account
    # output: mailing list which contain the user as an owner
    def list_owners (usr_eml):
        p = subprocess.Popen(['/usr/lib/mailman/bin/find_member','-w'],
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE,
                             stdin=subprocess.PIPE)
        out, err = p.communicate(usr_eml)
        print out
        m_list_usr_on = out.split( )
        print m_list_usr_on
    list_owners("my_email")
The output of this code is simply empty. On the other hand, if I run the code
/usr/lib/mailman/bin/find_member -w my_email 
directly from the shell command, I got the desired results. 
Could you explain to me the possible reasons of it?
Thank you!
 
    