Process file in AWS Lambda local and upload the same file to S3 bucket

Process file in AWS Lambda local and upload the same file to S3 bucket 

import boto3
s3 = boto3.resource('s3')
client_name = boto3.client('s3') 
my_bucket = s3.Bucket(bucket_source)
local_file_name = '/tmp/file.csv'
f = open(local_file_name, 'w')
        f.write("hello")
client_name.upload_file(local_file_name, bucket_target, file.csv")
f.close()