方式1

import logging

logger = logging.getLogger('simple_example')
logger.setLevel(logging.DEBUG)
# 创建日志保存文件
fh = logging.FileHandler('spam.log')
fh.setLevel(logging.DEBUG)
# 创建控制台日志输出
ch = logging.StreamHandler()
ch.setLevel(logging.ERROR)

# 设置日志格式
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
ch.setFormatter(formatter)
fh.setFormatter(formatter)

# add the handlers to logger
logger.addHandler(ch)
logger.addHandler(fh)

# 'application' code
logger.debug('debug message')
logger.info('info message')
logger.warning('warn message')
logger.error('error message')
logger.critical('critical message')

日志文件中的格式所用到的参数如下所示：