Initialize logging for Flask

setup_logging.py

def setup_logging():
    import logging
    import os
    from logging.handlers import RotatingFileHandler
    from logging import Formatter
    handler = RotatingFileHandler('log/flask.log', maxBytes=10000, backupCount=1)
    process_id = os.getpid()
    handler.setFormatter(Formatter(
        #'[%(asctime)s] [%(levelname)s]: %(message)s [in %(pathname)s:%(lineno)d]'  # for debug
        '[%(asctime)s #' + str(process_id) + '] [%(levelname)s]: %(message)s'
    ))
    handler.setLevel(logging.DEBUG)
    app.logger.addHandler(handler)

setup_logging()