AWS lambda function to start or stop EC2 based on SNS

lambda_function.py

import boto3
import json

region = 'us-west-2'
ec2 = boto3.client('ec2', region_name=region)

def lambda_handler(event, context):
    sns = event['Records'][0]['Sns']
    print('Message :' + sns['Message'])
    message = json.loads(sns['Message'])
    instanceIds = message['ec2InstanceIds']
    if (message['action'] == "Start"):
        ec2.start_instances(InstanceIds=instanceIds)
        print('Started your instances: ' + str(instanceIds))
    else:
        ec2.stop_instances(InstanceIds=instanceIds)
        print('Stoped your instances: ' + str(instanceIds))