Initial the global logger variable

def create_logger():
    """Initial the global logger variable"""
    global logger

    formatter = logging.Formatter('%(asctime)s|%(levelname)s|%(message)s')
    handler = TimedRotatingFileHandler(log_file, when="midnight", interval=1)
    handler.setFormatter(formatter)
    handler.setLevel(log_level)
    handler.suffix = "%Y-%m-%d"
    logger = logging.getLogger("sacplus")
    logger.setLevel(log_level)
    logger.addHandler(handler)