views3.py

def ajax_notes_update(request, notebook_pk, pk):
    notebook = get_object_or_404(Notebook, pk=notebook_pk)
    data = {}
    note = get_object_or_404(notebook.note_set, pk=pk)
    if request.method == "POST":
        form = NoteForm(request.POST, instance=note)
        post_url = reverse("ajax_notes_update", kwargs=dict(notebook_pk=notebook.pk, pk=pk))
        if form.is_valid():
            note = form.save()
            form = NoteForm()
            post_url = reverse("ajax_notes_create", kwargs=dict(notebook_pk=notebook.pk))
            data["fragments"] = {
                "#note-{}".format(note.pk): render_to_string("_note.html", {"note": note})
            }
    else:
        form = NoteForm(instance=note)
        post_url = reverse("ajax_notes_update", kwargs=dict(notebook_pk=notebook.pk, pk=pk))
    data["html"] = render_to_string("_note_form.html", {
        "note": note,
        "form": form,
        "post_url": post_url
    }, request)
    return JsonResponse(data)