is not JSON serializable

Question

I have the following ListView

import json
class CountryListView(ListView):
     model = Country

    def render_to_response(self, context, **response_kwargs)         


        

Answer 1

class CountryListView(ListView):
     model = Country

    def render_to_response(self, context, **response_kwargs):

         return HttpResponse(json.dumps(list(self.get_queryset().values_list('code', flat=True))),mimetype="application/json") 

fixed the problem

also mimetype is important.