def writelog(logfile, contentlist, mode='replace'):
        # type: (AnyStr, Union[AnyStr, List[AnyStr], Tuple[AnyStr]], AnyStr) -> None
        """write log"""
        if logfile is None:  # If logfile is not assigned, just print msg.
            print(UtilClass.print_msg(contentlist))
        else:
            if os.path.exists(logfile):
                if mode == 'replace':
                    os.remove(logfile)
                    log_status = open(logfile, 'w')
                else:
                    log_status = open(logfile, 'a')
            else:
                log_status = open(logfile, 'w')
            log_status.write(UtilClass.print_msg(contentlist))
            log_status.flush()
            log_status.close()