python - 如何在记录器格式化程序中输入变量？

Question

我目前有:

FORMAT = '%(asctime)s - %(levelname)s - %(message)s'
logging.basicConfig(format=FORMAT, datefmt='%d/%m/%Y %H:%M:%S', filename=LOGFILE, level=getattr(logging, options.loglevel.upper()))

...效果很好，但我正在尝试这样做:

FORMAT = '%(MYVAR)s %(asctime)s - %(levelname)s - %(message)s'

即使定义了 MYVAR，它也会抛出键盘错误。

有解决办法吗？ MYVAR 是一个常量，因此每次调用记录器时都必须传递它是一种耻辱。

谢谢!

Answer 1

你可以使用 custom filter :

import logging

MYVAR = 'Jabberwocky'


class ContextFilter(logging.Filter):
    """
    This is a filter which injects contextual information into the log.
    """
    def filter(self, record):
        record.MYVAR = MYVAR
        return True

FORMAT = '%(MYVAR)s %(asctime)s - %(levelname)s - %(message)s'
logging.basicConfig(format=FORMAT, datefmt='%d/%m/%Y %H:%M:%S')

logger = logging.getLogger(__name__)
logger.addFilter(ContextFilter())

logger.warning("'Twas brillig, and the slithy toves")

产量

Jabberwocky 24/04/2013 20:57:31 - WARNING - 'Twas brillig, and the slithy toves