### this should show you why quoting is not easy

import os


try:
    from shlex import quote # python3.x
except ImportError:
    from pipes import quote # python2.x


msg='  ";xmessage This is a Shell Command"  ';    


#os.system('espeak "' + msg + '"')  # Bad idea :-(

#os.system('espeak "' + quote(msg) + '"')  # Bad idea too !!!!  :-(

os.system('espeak '  + quote(msg) )  # Better :-))