def category_products(request, pk):
    try:
        queryset = Category.objects.prefetch_related('products')
        if queryset:
            category = queryset.get(pk=pk)
            products = Product.objects.filter(category=category)
        else:
            return HttpResponse("Oops! Not Found")
    except Category.DoesNotExist:
        return HttpResponse("Oops! Not Found")
    if products:
        context = "".join([f"{product.title} ===>>>> {product.upc}"
                           f"  |||| - {product.category.name} - |||| \\n"
                           for product in products])
        return HttpResponse(context)
    else:
        return HttpResponse("Oops! Not Found")

من برای سه حالت پیش اومده مجبور شم به این شکل رفتار کنم