Create Catalogs view

    def items(self, obj):

        cat, current_page = obj

        catalogs_list = Catalog.objects.filter(parent=cat).order_by("cat_type","cat_name")

        books_list = Book.objects.filter(catalog=cat).prefetch_related('authors','genres','series').order_by("title")

        # prefetch_related on sqlite on items >999 therow error "too many SQL variables"

        #books_list = Book.objects.filter(catalog=cat).prefetch_related('authors','genres','series').order_by("title")

        books_list = Book.objects.filter(catalog=cat).order_by("title")

        union_list = list(chain(catalogs_list,books_list))

        paginator = Paginator(union_list,settings.MAXITEMS)

        try:

            #    books={}                      

        # Сортируем

        if len(books)>0:

            books = books.prefetch_related('authors','genres','series').order_by('title','authors','-docdate')

            # prefetch_related on sqlite on items >999 therow error "too many SQL variables"

            #books = books.prefetch_related('authors','genres','series').order_by('title','authors','-docdate')

            books = books.order_by('title','authors','-docdate')

        # Фильтруем дубликаты

        #books = books.values()