title: Get notification when twilio call is picked up
body: <p>I'm building a twilio app and would like to get notified when a call made using twilio is picked up. I'm using the python api to make the call, like so:</p>
  
  <pre><code>call = client.calls.create(to=number,
                             from_="15555555555",
                             url=twiml_url,
                             status_callback=status_url)
  </code></pre>
  
  <p>This all works fine. I get notified when the call is made, by a POST to twiml_url and a POST to status_url when the call ends. In both of these cases I get passed the <em>CallStatus</em>, in the first with the value <em>'ringing'</em>, in the second <em>'completed'</em></p>
  
  <p>Now, I have read the API docs and know that they say that this is the expected behaviour. </p>
  
  <p>What I'm wondering is, is if there is any way to get a similar kicks for the other <em>CallStatus</em> changes? According to Twilio, all of the following are possible values for <em>CallStatus</em>:</p>
  
  <p><em>queued</em>, <em>ringing</em>, <em>in-progress</em>, <em>completed</em>, <em>failed</em>, <em>busy</em> or <em>no-answer</em></p>
  
  <p>It seems kind of pointless to have all the different <em>CallStatus</em>'s yet not provide callbacks for them. </p>
  
  <p>Ultimately, what I'm trying to achieve is to detect when a call is picked up. The only way I can see of doing this currently is by polling periodically and manually checking if the <em>CallStatus</em> has changed - hardly great.</p>