gistfile1.py

class UpdateOrCreateMixin(object):
    """
    A view mixin to allow views that use SingleObjectMixin to not fail if no pk/slug is provided.
    
    Primarily useful for making an UpdateView that can create objects too. For example::

        class MyView(UpdateOrCreateMixin, UpdateView):
            ...
        
        url(r'^add/$', MyView.as_view(), name='my-add-view'),
    """
    
    def get_object(self, *args, **kwargs):
        """
        Catch the failure exception of SingleObjectMixin and just return None.
        """
        try:
            return super(UpdateOrCreateMixin, self).get_object(*args, **kwargs)
        except AttributeError:
            return None