python 打印/保存日志

import logging

# 方法一  logging
# LOG_FORMAT = "%(asctime)s - %(levelname)s - %(message)s"
# DATE_FORMAT = "%m/%d/%Y %H:%M:%S %p"
#
# # logging.basicConfig(filename='my.log', level=logging.DEBUG, format=LOG_FORMAT, datefmt=DATE_FORMAT)
# logging.basicConfig(level=logging.DEBUG) # 默认日志输出到控制台，默认是WARNING
# logging.basicConfig(level=logging.DEBUG,
#                     format='%(asctime)s - %(filename)s[line:%(lineno)d] - %(levelname)s: %(message)s')
# # logging.basicConfig函数对日志的输出格式及方式做相关配置
#
# logging.debug("This is a debug log.")
# logging.info("This is a info log.")
# logging.warning("This is a warning log.")
# logging.error("This is a error log.")
# logging.critical("This is a critical log.")

# 方法二 日志器
# 创建日志器
def get_log():
    logger = logging.getLogger()
    logger.setLevel(level=logging.DEBUG)  # 处理器设置级别,然后可以对每个处理器单独设置级别
    # 创建两种不同的日志处理器
    console_handler = logging.StreamHandler()
    file_handler = logging.FileHandler("./log.txt", mode='a', encoding='utf-8')
    # 第三步 设置输出格式1
    console_fmt = '%(asctime)s - %(filename)s[line:%(lineno)d] - %(levelname)s: %(message)s'
    file_fmt = '%(asctime)s - %(filename)s[line:%(lineno)d] - %(levelname)s: %(message)s'
    # 第三步 设置输出格式2
    fmt1 = logging.Formatter(fmt=console_fmt)
    fmt2 = logging.Formatter(fmt=file_fmt)
    # 第三步 设置输出格式3
    console_handler.setFormatter(fmt1)
    file_handler.setFormatter(fmt2)

    # 单独设置每个处理器的级别
    file_handler.setLevel(logging.CRITICAL)
    console_handler.setLevel(logging.DEBUG)
    #  添加处理器
    logger.addHandler(console_handler)
    logger.addHandler(file_handler)
    # logger.debug("这是日志")
    # logger.warning('这是警告日志')
    # logger.critical('这是严重日志')
    return logger

if __name__ == '__main__':
    l = get_log()
    l.debug("这是日志")
    l.warning("这是日志")

详细参考：