<>logging 日志模块

使用 logging 的一般步骤：

import logging
logger = logging.getLogger()
hdlr = logging.FileHandler('/tmp/sendlog.txt')
formatter = logging.Formatter('%(asctime)s %(levelname)s %(message)s')
hdlr.setFormatter(formatter)
logger.addHandler(hdlr)
logger.setLevel(logging.NOTSET)

logger.debug('this is a DEBUG message!')
logger.error('this is an ERROR message!')

打开 /tmp/sendlog.txt 可以看到
2015-05-05 16:13:49,084 DEBUG this is a DEBUG message!
2015-05-05 16:13:49,108 ERROR this is an ERROR message!