Django全局名称'PageNotAnInteger'未定义

我有一个奇怪的问题。我有一个视图，它从Django REST Framework通过序列化器和分页器返回一些JSON。

我的视图如下所示（返回“国家”模型中的所有对象）：

@api_view(['GET'])
def country_list(request):
    """
    List all countries
    """
    if request.method == 'GET':

        geoname_ids = request.QUERY_PARAMS.get('geoname_ids')
        queryset = Countries.objects.all()
        paginator = Paginator(queryset, request.QUERY_PARAMS.get('limit'))
        page = request.QUERY_PARAMS.get('page')

        try:
            countries = paginator.page(page)
        except PageNotAnInteger:
            #If page is not an integer, deliver first page.
            countries = paginator.page(1)
        except EmptyPage:
            #If page is out of range
            #Delivery last page of results
            countries = paginator.page(paginator.num_pages)

        serializer_context = {'request': request}
        serializer = PaginatedCountrySerializer(countries, context=serializer_context)
        return Response(serializer.data)

这很好。

但是，我需要返回具有特定ID的国家/地区，我正在尝试这样做：

@api_view(['GET'])
def country_list(request):
    """
    List all countries
    """
    if request.method == 'GET':

        geoname_ids = request.QUERY_PARAMS.get('geoname_ids')
        queryset = Countries.objects.filter(country_geoname_id=geoname_ids)
        paginator = Paginator(queryset, request.QUERY_PARAMS.get('limit'))
        page = request.QUERY_PARAMS.get('page')

        try:
            countries = paginator.page(page)
        except PageNotAnInteger:
            #If page is not an integer, deliver first page.
            countries = paginator.page(1)
        except EmptyPage:
            #If page is out of range
            #Delivery last page of results
            countries = paginator.page(paginator.num_pages)

        serializer_context = {'request': request}
        serializer = PaginatedCountrySerializer(countries, context=serializer_context)
        return Response(serializer.data)

这显然是我用geonames_ids参数调用的URL。它给出一个错误：global name 'PageNotAnInteger' is not defined然后引用异常。

我的代码有问题吗？在更改查询集之前，为什么PageNotAnInteger可以正常工作找不到意义。