def get(self):
d = self.request.GET
if 'n' in d:
n = int(d['n'])
else:
n = None
res = SensorData.last_n_by_hours(d["sid"], n, False)
# write response
self.response.content_type = "application/json"
self.response.write(jsonify([x.json() for x in res]))
