Read file from s3.download_fileobj into memory

memory.py

s3 = boto3.client('s3')

## Reading a JSON file in memory
with tempfile.TemporaryFile() as data:
    s3.download_fileobj(bucket_name, 'tests/s3/key.json', data)
    data.seek(0)
    status = json.loads(data.read().decode('utf-8'))['status']

## Reading a CSV file in memory
with tempfile.TemporaryFile() as package_file:
    s3_client.download_fileobj(bucket_name, 'config/packages.csv', package_file)
    package_file.seek(0)
    file_as_string = package_file.read().decode('utf-8')
    csv_reader = csv.DictReader(io.StringIO(file_as_string))
    packages = [line['Package_Name'] for line in csv_reader]