LOG_FORMAT = "%(asctime)s %(name)-10s: [%(lineno)4d] %(levelname)-5s %(message)s"
_rootlogger = logging.getLogger()
-_fhandler = logging.FileHandler(LOG_FILENAME)
+_fhandler = logging.FileHandler(LOG_FILENAME, mode='w')
_shandler = logging.StreamHandler()
_formatter = logging.Formatter(LOG_FORMAT)
_fhandler.setFormatter(_formatter)