在 python 中使用多个参数进行日志记录

在 python 日志记录模块中，日志的格式如下：

formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')

**simple_example.py**
# 'application' code
logger.debug('debug message')
logger.info('info message')
logger.warning('warn message')

其输出如下：

OUTPUT:

2005-03-19 15:10:26,618 - simple_example - DEBUG - debug message
2005-03-19 15:10:26,620 - simple_example - INFO - info message
2005-03-19 15:10:26,695 - simple_example - WARNING - warn message

我只是想知道是否有任何方法可以不在末尾而是在中间添加多条消息，即类似

 My custom message 1  - simple_example - DEBUG - my custom message 2

有什么办法可以将其格式化为：

formatter = logging.Formatter('%(message1)s - %(name)s - %(levelname)s - %(message2)s')

任何帮助，将不胜感激

您可以编写自己的 Formatter 类并将额外消息作为 kwargs 传递：

import logging

class MyFormatter(logging.Formatter):
    def format(self, record):
        record.message2 = record.args.get("message2")
        return super().format(record)

logger = logging.getLogger('test')
ch = logging.StreamHandler()
formatter = MyFormatter('%(asctime)s - %(message2)s - %(name)s - %(levelname)s - %(message)s')
ch.setFormatter(formatter)
ch.setLevel(logging.ERROR)
logger.addHandler(ch)

logger.error("debug message", {"message2": "Blub"})

Output:

2019-02-08 14:33:50,487 - Blub - 测试 - 错误 - 调试消息

Edit:我不知道为什么这不能在 INFO 级别上开箱即用，但您可以执行以下操作，这将起作用：

import logging

class MyFormatter(logging.Formatter):
    def format(self, record):
        record.message2 = record.args.get("message2")
        return super().format(record)

logger = logging.getLogger('test')
ch = logging.StreamHandler()
ch.setFormatter(MyFormatter('%(asctime)s - %(message2)s - %(name)s - %(levelname)s - %(message)s'))
logging.basicConfig( level=logging.INFO, handlers=[ch] )

logger.info("debug message", {"message2": "Blub"})

Output:

2019-02-11 12:53:17,014 - Blub - 测试 - INFO - 调试消息

Edit 2:为此，无需提供字典即可工作message2，您可以按如下方式更改代码：

import logging

class MyFormatter(logging.Formatter):
    def format(self, record):
        record.message2 = ""
        if(record.args):
            record.message2 = record.args.get("message2", "Fallback Value")
        return super().format(record)

logger = logging.getLogger('test')
ch = logging.StreamHandler()
ch.setFormatter(MyFormatter('%(asctime)s - %(message2)s - %(name)s - %(levelname)s - %(message)s'))
logging.basicConfig( level=logging.INFO, handlers=[ch] )

logger.info("debug message", {"message2": "Blub"})
logger.info("This is my sample log")
logger.info("This is my sample log", {"hello": "World"})

Output:

2019-02-11 13:20:53,419 - Blub - test - INFO - debug message
2019-02-11 13:20:53,419 -  - test - INFO - This is my sample log
2019-02-11 13:20:53,419 - Fallback Value - test - INFO - This is my sample log