docs: def query(self, jsonq, operator="and", count=False):
          """
          returns a Django orm query from json input:
          {
          "app": "auth",
          "model": "User",
          "filters": {
              "is_superuser": False,
              "username__icontains": "foo"
          }
          """
          model = self._get_model(jsonq["app"], jsonq["model"])
          fdict = jsonq["filters"]
          filters = []
          try:
              q = model.objects.none()
          except Exception as e:
              self.err(e)
          for label in fdict:
              kwargs = {label: fdict[label]}
              filters.append(Q(**kwargs))
          if filters == []:
              try:
                  q = model.objects.all()
                  return q
              except Exception as e:
                  self.err(e)
          else:
              fq = Q()
              for f in filters:
                  if operator == "and":
                      fq = fq & f
                  elif operator == "or":
                      fq = fq | f
              if count is False:
                  try:
                      q = model.objects.filter(fq)
                  except Exception as e:
                      self.err(e)
              else:
                  try:
                      q = model.objects.filter(fq).count()
                  except Exception as e:
                      self.err(e)
          return q