Set up basic (INFO level) and debug logfiles

def setup_logging(logfile_path):
    """
    Set up basic (INFO level) and debug logfiles
    """
    date_fmt = "%y-%m-%d (%a) %H:%M:%S"

    std_formatter = logging.Formatter('%(asctime)s:%(levelname)s:%(message)s',
                                      date_fmt)

    # Get to the following size before splitting log into multiple files:
    log_chunk_bytesize = 5e6

    info_logfile = logging.handlers.RotatingFileHandler(logfile_path,
                                                        maxBytes=log_chunk_bytesize,
                                                        backupCount=10)
    info_logfile.setFormatter(std_formatter)
    info_logfile.setLevel(logging.DEBUG)

    stdout_log = logging.StreamHandler()
    stdout_log.setLevel(logging.DEBUG)
    stdout_log.setFormatter(std_formatter)

    # Set up root logger
    logger = logging.getLogger()
    logger.handlers = []
    logger.setLevel(logging.DEBUG)
    logger.addHandler(info_logfile)
    logger.addHandler(stdout_log)
    logging.getLogger('iso8601').setLevel(
        logging.ERROR)  # Suppress iso8601 debug log.
    return logger