This second XML example tells Plivo to say “Wow” three times. Example Request 
from plivo import plivoxml

response = (plivoxml.ResponseElement()
            .add(plivoxml.SpeakElement('Wow.').set_loop(3)))
print(response.to_string())
Response 
<Response>
    <Speak loop="3">Wow</Speak>
</Response>