Automatic LED Control

import email_conf
from boltiot import Email,Bolt
import json, time, math, statistics
def compute_bounds(history_data,frame_size,factor);
  if len(history_data)<frame_size :
    return None
  if len(history_data)<frame_size : 
    del history_data[0:len(history_data)-frame_size]
  Mn=statistics.mean(history_data)
  Variance=0
  for data in history_data :
    Variance += math.pow((data-Mn),2)
  Zn = factor * math.sqrt(Variance / frame_size)
  High_bound = history_data[frame_size-1]+Zn
  Low_bound = history_data[frame_size-1]-Zn
  return [High_bound,Low_bound]
  
  mybolt = Bolt(email_conf.API_KEY, email_conf.DEVICE_ID)
  history_data=[]
  
  while True:
    response = mybolt.analogRead('A0')
    data= json.loads(response)
    if data['success'] != 1:
      print("There was an error while retrieving the data.")
      print("This is the error: "+data['value'])
      time.sleep(10)
      continue
      
    print ("This is the value: "+data['value'])
    sensor_value=0
    try:
      sensor_value = int(data['value']
    except e:
      print("There was an error while parsing the response: ",e)
      continue
      
    bound = compute_bounds(history_data,email_conf.FRAME_SIZE,email_conf.MUL_FACTOR)
    if not bound:
      required_data_count=email_conf.FRAME_SIZE-len(history_data)
      print("Not enough data to calculate Z-score.Need ",required_data_count," more data points.")
      history_data.append(int(data['value']))
      time.sleep(10)
      continue
      
    try:
      if sensor_value > bound[0] :
        print ("The light intensity increased suddenly.Someone turned on the lights.")
        response = mybolt.digitalWrite('0','LOW')
      elif sensor_value < bound[1] :
        print ("The light intensity decreased suddenly.Someone turned off the lights.")
        response = mybolt.digitalWrite('0','HIGH')
      history_data.append(sensor_value);
    except Exception as e:
      print ("Error occured: ",e)
    time.sleep(10)