python logging模块用法

推荐两篇比较清晰的博客：

https://zhuanlan.zhihu.com/p/56968001

https://www.jianshu.com/p/feb86c06c4f4

简单来说，即：

1、怎么有选择性的输出信息

2、怎么有选择性的记录信息

简单、常见用法

import logging
 
logger = logging.getLogger(__name__)
logger.setLevel(level=logging.DEBUG)
 
# Formatter
fmt = "%(asctime)-15s %(levelname)s %(filename)s %(lineno)d %(process)d %(message)s"  # 设置log文本形式
datefmt = "%a %d %b %Y %H:%M:%S"    # 设置时间
formatter = logging.Formatter(fmt, datefmt)    # 创建日志formatter

 
# FileHandler
file_handler = logging.FileHandler('result.log')
file_handler.setFormatter(formatter)
file_handler.setLevel('DEBUG')
logger.addHandler(file_handler)    # 添加到logger中
 
# StreamHandler
stream_handler = logging.StreamHandler()
stream_handler.setFormatter(formatter)
stream_handler.setLevel('INFO')
logger.addHandler(stream_handler)    # 添加到 logger中
 
 
# Log
logger.info('Start')
logger.warning('Something maybe fail.')