Django contstruct object - django

Question

I'm working on a backend for an app and writing a function to retrieve data from several tables and then construct a httpresponse from that.
What I would like to do is get a vaccine, then all the diseases for that vaccine and then construct something(object, list, dict, ...) containing everything.
What I've got so far is:
def vaccinepack(request, country_id):
vaccines = Vaccine.objects.filter(diseases__countries__id=country_id)
diseases = []
json = serializers.get_serializer("json")()
response = HttpResponse()
for v in vaccines:
dis = Disease.objects.filter(vaccine=v.id)
disdata = ""
for d in dis:
disdata += json.serialize([d], ensure_ascii=False)
json.serialize([v, disdata], ensure_ascii=False, stream=response)
return response
But I'm running to trouble when serialising [v, disdata].
'list' object has no attribute '_meta'.
I'm rather new to Django so I'm not sure what's the proper way of doing this.
Here's my models:
class Disease(models.Model):
name = models.CharField(max_length=100)
text = models.CharField(max_length=2000)
countries = models.ManyToManyField(Country, blank=True)
def __unicode__(self):
return self.name
class Vaccine(models.Model):
name = models.CharField(max_length=100)
text = models.CharField(max_length=2000)
diseases = models.ManyToManyField(Disease, blank=True)
def __unicode__(self):
return self.name

Answer 1

The immediate cause of your error message is because you're passing a list object to the Django serializer, but it's expecting a QuerySet.
What I would do is to build up the data structure as a series of nested Python dictionaries, and then convert it all to JSON at the end with json.dumps(). (Note that's the actual built-in json library, which you've shadowed with the serializer.) Something like (untested):
serializer = serializers.get_serializer('python')
vaccine_list = serializer.serialize(vaccines)
for i, v in enumerate(vaccines):
diseases = v.diseases.all()
disease_list = serializer.serialize(diseases)
vaccine_list[i]['fields']['diseases'] = disease_list
data = json.dumps(vaccine_list)