How can i make the python to wait till i complete speaking? -

i writing program recognise speech microphone , code process accordingly. code wrote purpose below.

import speech_recognition sr import webbrowser import pyttsx time import sleep  engine = pyttsx.init() engine.setproperty('rate', 70) r = sr.recognizer()  def recognize(audio):     try:         return r.recognize(audio)     except lookuperror, e:         print e     return '' sr.microphone() source:     while true:         engine.say("hi how can ?")         sleep(0.15)         print "start speaking"         audio = r.listen(source)         words = recognize(audio)         print("you said " + words)         if words == "facebook":             engine.say("shall open facebook page ?")             engine.runandwait()             audio = r.listen(source)             words = recognize(audio)             if words == "yes":                 webbrowser.open('https://www.facebook.com')         elif words == "stop":             break 

here tried sleep before engine speaks can see text start speaking getting printed. instead of sleep, there nice way capture speech in microphone , wait till or long silence?

this method:

        engine.runandwait() 

waits speech complete. need use not after engine.say("shall open facebook page ?"), after engine.say("hi how can ?") instead of sleep