def post_comment(request, interview_id, applicant_id):
  if request.POST:
    text = str(request.POST['add_comment'])
    interview = Interview.objects.get(id = interview_id)
    applicant = Applicant.objects.get(id = applicant_id)
    response = Response.objects.filter(interview = interview, applicant = applicant)
    date = datetime.datetime.now()
comment = Comment(
  user = request.user,
  applicant = applicant,
  interview = interview,
  response = response,
  comment = text,
  created_at = date,
)

class Response(models.Model):
  video_guid = models.CharField(max_length=32)
  interview = models.ForeignKey(Interview)
  applicant = models.ForeignKey(Applicant)
  question = models.ForeignKey(Question)


class Comment(models.Model):
  user = models.ForeignKey(User)
  applicant = models.ForeignKey(Applicant)
  interview = models.ForeignKey(Interview)
  response = models.ForeignKey(Response)
  comment = models.TextField(default='')
  created_at = models.DateTimeField(default=datetime.datetime.now())

for i in response:
    Comment.objects.create(
           user = request.user,
           applicant = applicant,
           interview = interview,
           response = i,
           comment = text,
           created_at = date)

c = Comment.objects.get(pk=1)
c.response.interview # interview object

# Get all the comments for where the interview objects primary key is 1
c = Comment.objects.filter(response__interview__pk=1)

r = Response.objects.get(pk=1)
r.comment_set.all() # all comments for this response