DSmartHome-api Lambda handler

import boto3
import json
import time

print('Loading function')
dynamodb = boto3.resource('dynamodb')

def respond(err, res=None):
    return {
        'statusCode': '400' if err else '200',
        'body': err.message if err else json.dumps(res),
        'headers': {
            'Content-Type': 'application/json',
        },
    }

def lambda_handler(event, context):
    table = dynamodb.Table('dsmarthome')
    
    table.update_item(
        Key={
            'location': '829Seabury',
            'device': event['device']
        },
        UpdateExpression="set latest = :latest, latesttime = :latesttime",
        ExpressionAttributeValues={
            ':latest': event['value'],
            ':latesttime': int(time.time())
        },
        ReturnValues="UPDATED_NEW"
    )