Aqui está o que eu quero fazer:

O usuário carrega um arquivo csv no bucket do AWS S3.Após o upload do arquivo, o bucket do S3 chama a função lambda que eu criei.Minha função lambda lê o conteúdo do arquivo csv e envia um email com o conteúdo e as informações do arquivo

Ambiente local

Framework sem servidor versão 1.22.0

Python 2.7

Aqui está o meu arquivo serverless.yml

service: aws-python # NOTE: update this with your service name

provider:
  name: aws
  runtime: python2.7
  stage: dev
  region: us-east-1
  iamRoleStatements:
        - Effect: "Allow"
          Action:
              - s3:*
              - "ses:SendEmail"
              - "ses:SendRawEmail"
              - "s3:PutBucketNotification"
          Resource: "*"

functions:
  csvfile:
    handler: handler.csvfile
    description: send mail whenever a csv file is uploaded on S3 
    events:
      - s3:
          bucket: mine2
          event: s3:ObjectCreated:*
          rules:
            - suffix: .csv

e aqui está minha função lambda:

import json
import boto3
import botocore
import logging
import sys
import traceback
import csv

from botocore.exceptions import ClientError
from pprint import pprint
from time import strftime, gmtime
from json import dumps, loads, JSONEncoder, JSONDecoder


#setup simple logging for INFO
logger = logging.getLogger()
logger.setLevel(logging.INFO)

from botocore.exceptions import ClientError

def csvfile(event, context):
    """Send email whenever a csvfile is uploaded to S3 """
    body = {}
    emailcontent = ''
    status_code = 200
    #set email information
    email_from = '****@*****.com'
    email_to = '****@****.com'
    email_subject = 'new file is uploaded'
    try:
        s3 = boto3.resource(u's3')
        s3 = boto3.client('s3')
        for record in event['Records']:
            filename = record['s3']['object']['key']
            filesize = record['s3']['object']['size']
            source = record['requestParameters']['sourceIPAddress']
            eventTime = record['eventTime']
        # get a handle on the bucket that holds your file
        bucket = s3.Bucket(u'mine2')
        # get a handle on the object you want (i.e. your file)
        obj = bucket.Object(key= event[u'Records'][0][u's3'][u'object'][u'key'])
        # get the object
        response = obj.get()
        # read the contents of the file and split it into a list of lines
        lines = response[u'Body'].read().split()
        # now iterate over those lines
        for row in csv.DictReader(lines):    
            print(row)
            emailcontent = emailcontent + '\n' + row 
    except Exception as e:
        print(traceback.format_exc())
        status_code = 500
        body["message"] = json.dumps(e)

    email_body = "File Name: " + filename + "\n" + "File Size: " + str(filesize) + "\n" +  "Upload Time: " + eventTime + "\n" + "User Details: " + source + "\n" + "content of the csv file :" + emailcontent
    ses = boto3.client('ses')
    ses.send_email(Source = email_from,
        Destination = {'ToAddresses': [email_to,],}, 
            Message = {'Subject': {'Data': email_subject}, 'Body':{'Text' : {'Data': email_body}}}
            )
    print('Function execution Completed')

não sei o que fiz de errado, porque a parte quando obtive informações sobre o arquivo funciona bem; é quando adiciono a parte de leitura que a função lambda não retorna nada