AWS Lambda Random Letter Add

lambda_handler.py

import json
import urllib.parse
import boto3

#need these to return random string
import random
import string

print('Loading function')

s3 = boto3.client('s3')


def lambda_handler(event, context):
    # Get the object from the event and show its content type
    bucket = event['Records'][0]['s3']['bucket']['name']
    print("Bucket name: ", bucket)
    object_name = event['Records'][0]['s3']['object']['key']
    print("Object name: ", object_name)
    key = urllib.parse.unquote_plus(event['Records'][0]['s3']['object']['key'], encoding='utf-8')
    print("Key: ", key)
    random_letter = random.choice(string.ascii_letters) + "_"
    new_key = random_letter + key
    print("Proposed new name: ", new_key)
    try:
        print("Using waiter to wait for object to persist thru s3 service…")
        waiter = s3.get_waiter('object_exists')
        waiter.wait(Bucket=bucket, Key=key)
        response = s3.get_object(Bucket=bucket, Key=key)
        s3.copy_object(Bucket=bucket, CopySource= "{}/{}".format(bucket, key), Key=new_key)
        s3.delete_object(Bucket=bucket, Key=key)
        print("Old name: {}".format(key))
        print("New name: {}".format(new_key))
        return response['ContentType']
    except Exception as e:
        print(e)
        print('Error getting object {} from bucket {}. Make sure they exist and your bucket is in the same region as this function.'.format(key, bucket))
        raise e