using Python with Twilio how can I implement reject() and callback?

Question

I want to call my Twilio number from my cellphone, Twilio recognizes my number, rejects the call and then calls me back. Here is the code:

@application.route("/test", methods=['GET', 'POST'])
def test():
    whitelist = ['81808730xxxx', '44753810xxxx', '+44753810xxxx', '+44792834xxxx', '44792834xxxx']
    call_from = request.values.get('From', 'None')
    if call_from in whitelist:
        # "<Response><Reject /></Response>"
        resp = twilio.twiml.Response()
        resp.reject()
        time.sleep( 10 )
        account_sid = "account_sid"
        auth_token = "account_auth_token"
        client = TwilioRestClient(account_sid, auth_token)
        call = client.calls.create(to=call_from, from_="+1646480xxxx", url="https://zshizuka.herokuapp.com/gather")
        print call.sid
    else:
        resp = twilio.twiml.Response()
        call_to = "+44792834xxxx"
        resp.dial(call_to)
        #return json.dumps({'success':True}), 200
        return str(resp)

This produces the dreaded response: "We are sorry a system error has occurred. Goodbye".

If, however, I dial the number and hangup after the first ring it works perfectly. So I am assuming that the problem is with the reject verb. As you can see I have tried with and without twiml.

I would like to get a busy signal, call rejected (so no cost to cell phone bill) and then callback.

Grateful for help.

Megan Speir Megan Speir · Accepted Answer · 2016-06-15T00:12:16

I'd love to better understand your use case but I'm going to give this a go using the Twilio Python Helper Library.

As far as <Reject> TwiML goes, you can do something like this and be sure to specify a reason setting it to 'busy':

from flask import Flask
from flask import request

from twilio import twiml

account_sid = "YOU_ACCOUNT_SID"
auth_token = "YOUR_ACCOUNT_TOKEN"
client = TwilioRestClient(account_sid, auth_token)

app = Flask(__name__)

@app.route('/test', methods=["GET", "POST"])
def test():
    whitelist = ['+14151XXXXXX', '+14152XXXXXX']
    call_from = request.form['From']
    if call_from in whitelist:
        resp = twiml.Response()
        resp.reject(reason="busy")
        return str(resp)
    else:
        resp = twiml.Response()
        call_to = "+14153XXXXXX"
        resp.dial(call_to)
        return str(resp)

if __name__ == "__main__":
    app.run()

As there is no callback within <Reject> you will have a few options as to how you can proceed.

If you're using Python 3.3 or greater you might consider doing the whole process with asyncio.

With older versions of Python, then I would recommend you try completing the client call through a task queue as demonstrated in this post.

Please let me know if this helps at all.

using Python with Twilio how can I implement reject() and callback?

1 Answers