python - is not JSON serializable -

i have following listview

import json class countrylistview(listview):      model = country      def render_to_response(self, context, **response_kwargs):           return json.dumps(self.get_queryset().values_list('code', flat=true)) 

but following error:

[u'ae', u'ag', u'ai', u'al', u'am',  u'ao', u'ar', u'at', u'au', u'aw',  u'az', u'ba', u'bb', u'bd', u'be', u'bg',  u'bh', u'bl', u'bm', u'bn', '...(remaining elements truncated)...']  not json serializable 

any ideas ?

i'll add more detailed answer.

it's worth noting queryset.values_list() method doesn't return list, object of type django.db.models.query.valueslistqueryset, in order maintain django's goal of lazy evaluation, i.e. db query required generate 'list' isn't performed until object evaluated.

somewhat irritatingly, though, object has custom __repr__ method makes list when printed out, it's not obvious object isn't list.

the exception in question caused fact custom objects cannot serialized in json, you'll have convert list first, with...

my_list = list(self.get_queryset().values_list('code', flat=true)) 

...then can convert json with...

json_data = json.dumps(my_list) 

you'll have place resulting json data in httpresponse object, which, apparently, should have content-type of application/json, with...

response = httpresponse(json_data, content_type='application/json') 

...which can return function.