python logging

import logging

# # logging 级别
# logging.debug('xxx')
# logging.info('xxx')
# logging.warning('warnging')
# logging.error('error')
# logging.critical('critical')

# # 用 logging.basicConfig() 设置基本格式
# logging.basicConfig(format='%(asctime)s - %(pathname)s[line:%(lineno)d] - %(levelname)s: %(message)s',
#                     level=logging.DEBUG)
# logging.debug('debug')
# logging.info('info xin xi')
# logging.warning('warnging xin xi')
# logging.error('error xin xi')
# logging.critical('crtical xin xi')

# 用 logging.basicConfig() 保存到log文件
# logging.basicConfig(level=logging.DEBUG,
#                     filename='new.log',
#                     filemode='a', ## 写的模式， w,a
#                     format='%(asctime)s - %(pathname)s[line:%(lineno)d] - %(levelname)s: %(message)s',
#                     )

# logging.debug('debug')
# logging.info('info')
# logging.warning('warning')
# logging.error('error')
# logging.critical('critical')

# 老顽童
# logging.basicConfig(level=logging.INFO,format='%(asctime)s - %(name)s - %(levelname)s - %(message)s')
# logger = logging.getLogger(__name__)
#
# logger.info("info")
# logger.debug("debug")
# logger.warning('waring')
# logger.info("finish")
# 输出到文件
# logger = logging.getLogger()
# logger.setLevel(level=logging.INFO)
# handler = logging.FileHandler("log.txt")
# handler.setLevel(logging.INFO)
# formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
# handler.setFormatter(formatter)
# logger.addHandler(handler)
#
# logger.info('iiii')
# logger.debug('dddd')
# logger.warning('wwww')
# logger.info('iiii')

# 输出到屏幕和文件
logger = logging.getLogger()
logger.setLevel(level = logging.INFO)
handler = logging.FileHandler("log.txt")
handler.setLevel(logging.INFO)


console = logging.StreamHandler()
console.setLevel(logging.INFO)

logger.addHandler(handler)
logger.addHandler(console)

logger.info("Start print log")
logger.debug("Do something")
logger.warning("Something maybe fail.")
logger.info("Finish")

参考：

http://www.cnblogs.com/zhbzz2007/p/5943685.html

https://www.cnblogs.com/liujiacai/p/7804848.html