Crackin' article - simple and clear with the code snippets showing exactly what is needed and no more (no useless clutter to obstruct the point). Really got me going in the right direction along with the advanced tutorial in the docs here - https://docs.python.org/3/howto/logging.html#advanced-logging-tutorial

If anyone else is reading, to implement in a classic package structrue then you take the bit for 'app.py' and place it in the __init__.py i.e.:

import logger

log = logger.setup_applevel_logger(file_name = 'app_debug.log')