out

bundle.data['max_responses'] ->  None
bundle.obj.max_responses ->  22

resources.py

class EventResource (ModelResource):
    max_responses = fields.IntegerField('max_responses', null=True)
    ...
    def obj_update (self, bundle, request=None, **kwargs):
        print "bundle.data['max_responses'] -> ", bundle.data.get('max_responses')
        bundle = super (EventResource, self).obj_update(bundle, request, **kwargs)
        print "bundle.obj.max_responses -> ", bundle.obj.max_responses
        return bundle