csv.py

import boto3
import json
import csv
import io

def lambda_handler(event, context):
    s3 = boto3.resource('s3')
    content_object = s3.Object('src-bucket', 'src-file.json')
    file_content = content_object.get()['Body'].read().decode('utf-8')
    lines = file_content.splitlines()

    items = {}
    for line in lines:
        json_line = json.loads(line)
        customer = json_line["Customer"]
        items[customer["Email"]] = customer
    
    toCSV = list(items.values())
    keys = toCSV[0].keys()
    output = io.StringIO()
    dict_writer = csv.DictWriter(output, keys)
    dict_writer.writeheader()
    dict_writer.writerows(toCSV)
    s3.Object('my-items', 'items.csv').put(Body=output.getvalue())
    
    # Generate the URL to get 'key-name' from 'bucket-name'
    url = boto3.client('s3').generate_presigned_url(
        ClientMethod='get_object',
        ExpiresIn= 3600,
        Params={
            'Bucket': 'my-items',
            'Key': 'items.csv'
        }
    )

    return url