views.py

def book_list(request: HttpRequest) -> HttpResponse:
    if request.method == "GET":
        books = Book.objects.filter(visible=True)
        if "author" in request.GET:
            books = books.filter(author__icontains=request.GET["author"])
        if "title" in request.GET:
            books = books.filter(title__icontains=request.GET["title"])

        response_data = [book_to_json(book) for book in books]
        return JsonResponse(response_data, safe=False)

    elif request.method == "POST":
        if request.content_type != "application/json":
            return HttpResponse(status=HTTPStatus.UNSUPPORTED_MEDIA_TYPE)
        request_data = json.loads(request.body)
        book = book_from_json(request_data)
        book.save()
        return HttpResponse(status=HTTPStatus.CREATED)

    else:
        return HttpResponseNotAllowed(["GET", "POST"])


def book_detail(request: HttpRequest, isbn: str) -> HttpResponse:
    books = Book.objects.filter(visible=True)

    book = get_object_or_404(books, isbn=isbn)
    response_data = book_to_json(book)
    return JsonResponse(response_data)