Python日志记录：传播低于当前日志记录程序级别的消息

Question

我希望将具有特定记录器名称、特定级别和更高级别（例如info和更高级别）的消息记录到特定日志处理程序（例如文件处理程序），同时仍将所有日志消息发送到控制台。Python是2.7版。

到目前为止，我尝试创建了两个记录器：

• 根记录器
• 命名记录器

对于根记录器，我附加了logging.StreamHandler，并将日志级别设置为logging.debug。

然后，我将一个处理程序附加到命名记录器，并将该记录器的级别设置为logging.info。

当我现在调用使用命名记录器的模块时，我不再获得传播到根记录器的debug日志。

注意：extraLogger在这里有一个StreamHandler来演示这个问题。在我的生产代码中，我会使用一个文件处理程序

import logging

def do_logging(turn):
    logger = logging.getLogger('extra')
    logger.info('some info turn %d' % turn) 
    logger.debug('this is debug fudge turn %d' % turn)

rootLogger = logging.getLogger()
handler = logging.StreamHandler()
rootFormatter = logging.Formatter('root - %(levelname)s: %(msg)s')
handler.setFormatter(rootFormatter)
rootLogger.addHandler(handler)
rootLogger.setLevel(logging.DEBUG)

do_logging(1)

extraLogger = logging.getLogger('extra')
extraHandler = logging.StreamHandler()
extraFormatter = logging.Formatter('extra - %(levelname)s: %(msg)s')
extraHandler.setFormatter(extraFormatter)
extraLogger.addHandler(extraHandler)
extraLogger.setLevel(logging.INFO)

do_logging(2)

实际产出：

root - INFO: some info turn 1
root - DEBUG: this is debug fudge turn 1
extra - INFO: some info turn 2
root - INFO: some info turn 2

我想要的输出：

root - INFO: some info turn 1
root - DEBUG: this is debug fudge turn 1
extra - INFO: some info turn 2
root - INFO: some info turn 2
root - DEBUG: this is debug fudge turn 2

我怀疑自定义过滤器在这种情况下会有帮助，但我不知道如何...

Answer 1

您可以像这样使用Robert的LevelFilter：

# Put the Filter on the Handler so only INFO and higher is handled
extraHandler.addFilter(LevelFilter(logging.INFO))

# Let the Logger process everything (so it can propagate records to root)
extraLogger.setLevel(logging.DEBUG)

import logging

class LevelFilter(logging.Filter):
    """
    https://stackoverflow.com/a/7447596/190597 (robert)
    """
    def __init__(self, level):
        self.level = level

    def filter(self, record):
        return record.levelno >= self.level

def do_logging(turn):
    logger = logging.getLogger('extra')
    logger.info('some info turn %d' % turn) 
    logger.debug('this is debug fudge turn %d' % turn)

rootLogger = logging.getLogger()
handler = logging.StreamHandler()
rootFormatter = logging.Formatter('root - %(levelname)s: %(msg)s')
handler.setFormatter(rootFormatter)
rootLogger.addHandler(handler)
rootLogger.setLevel(logging.DEBUG)
do_logging(1)

extraLogger = logging.getLogger('extra')
extraHandler = logging.StreamHandler()
extraFormatter = logging.Formatter('extra - %(levelname)s: %(msg)s')
extraHandler.setFormatter(extraFormatter)
extraLogger.addHandler(extraHandler)

# Put the Filter on the Handler so only INFO and higher is handled
extraHandler.addFilter(LevelFilter(logging.INFO))

# Handle everything (so it can propagate to root)
extraLogger.setLevel(logging.DEBUG)
do_logging(2)