title: Disable pagination when not requesting any page in djangorestframework
body: <p>I wrote a pagination class like below for a ListView API.</p>
  
  <pre><code>class PhotoListPagination(PageNumberPagination):
     page_size = 100
     page_size_query_param = 'page_size'
     max_page_size = 10000
  </code></pre>
  
  <p>and use it in my API view as <code>pagination_class</code>:</p>
  
  <pre><code>class UserSinglePhotoAPIView(ListAPIView):
      model = Photo
      serializer_class = PhotoSerializer
      pagination_class = PhotoListPagination
  
      def get_queryset(self):
          return Profile.objects.get(auth_user__username=self.kwargs['username']).get_single_photos()
  </code></pre>
  
  <p>as I send a <code>GET</code> request to <code>/link/to/my/API/end-point?page=1</code> or any other page number, it works pretty well. currently when <code>page</code> has no value (sending request to <code>/link/to/my/API/end-point</code>) it shows page 1.  But I need to have all the results without pagination when I not set <code>page</code> key in the request.</p>
  
  <p>Is it possible?  </p>
  
  <p>Any help will be appreciated. </p>