Django Rest Framework: 'function' object has no attribute 'as_view'

To add to Tim Saylor point,

https://docs.djangoproject.com/en/dev/topics/class-based-views/intro/#id1

To decorate every instance of a class-based view, you need to decorate the class definition itself. To do this you apply the decorator to the dispatch() method of the class.

A method on a class isn’t quite the same as a standalone function, so you can’t just apply a function decorator to the method – you need to transform it into a method decorator first. The method_decorator decorator transforms a function decorator into a method decorator so that it can be used on an instance method. For example:

from django.contrib.auth.decorators import login_required
from django.utils.decorators import method_decorator
from django.views.generic import TemplateView

class ProtectedView(TemplateView):
    template_name = 'secret.html'

    @method_decorator(login_required)
    def dispatch(self, *args, **kwargs):
        return super(ProtectedView, self).dispatch(*args, **kwargs)

Since this is the #1 hit on google for this error message and there's a more subtle and probably common cause for it than the OPs, I'm posting this comment here.

This error can also be caused by using a standard view decorator on a class based view instead of on the __dispatch__ method within the view.

def TestView(View): should be class TestView(View):. As it stands, you define a function called TestView which takes an argument called View -- its body defines an inner function, then returns None.