title: Django Rest Framework: empty request.data
body: <p>I have the following code for a view of DRF:</p>
  
  <pre><code>from rest_framework import viewsets
  
  class MyViewSet(viewsets.ViewSet):
  
      def update(self, request, pk = None):
          print pk
          print request.data
  </code></pre>
  
  <p>I call the URL via <em>python-requests</em> in the following way:</p>
  
  <pre><code>import requests
  payload = {"foo":"bar"}
  headers = {'Content-type': 'application/json'}
  r = requests.put("https://.../myPk", data= payload, headers=headers)
  </code></pre>
  
  <p>but when the request is received from the server, request.data is empty. Here there is the output:</p>
  
  <pre><code>myPk
  &lt;QueryDict: {}&gt;
  </code></pre>
  
  <p>How can I fix this problem?</p>