Python 即使处理程序级别设置为调试，记录器也不显示调试级别消息

Question

我正在尝试创建一个打印“调试”消息的记录器。我已经定义了具有正确级别集的处理程序。它仍然只打印警告级别及更高级别。

这是我的代码：

import logging

# Create a custom logger
logger = logging.getLogger(__name__)

# Create handlers
c_handler = logging.StreamHandler()
f_handler = logging.FileHandler('file.log')
c_handler.setLevel(logging.DEBUG)
f_handler.setLevel(logging.DEBUG)

# Create formatters and add it to handlers
c_format = logging.Formatter('%(name)s - %(levelname)s - %(message)s')
f_format = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
c_handler.setFormatter(c_format)
f_handler.setFormatter(f_format)

# Add handlers to the logger
logger.addHandler(c_handler)
logger.addHandler(f_handler)

logger.warning('This is a warning')
logger.error('This is an error')
logger.info('This is an info')
logger.debug('This is a debug')

虽然这是我得到的控制台输出：

__main__ - WARNING - This is a warning
__main__ - ERROR - This is an error

Process finished with exit code 0

我发现关于这个问题，但在那种情况下，处理程序没有设置。我的处理程序已设置。

这是怎么回事？

PS：代码是 this page 部分“使用处理程序”部分的略微改动版本。

Answer 1

您忘记设置 logger 等级

import logging

# Create a custom logger
logger = logging.getLogger(__name__)

# Create handlers
c_handler = logging.StreamHandler()
f_handler = logging.FileHandler('file.log')

# handler level is different from logger level
c_handler.setLevel(logging.DEBUG)
f_handler.setLevel(logging.DEBUG)

# this will do the trick
logger.setLevel(logging.DEBUG)

# Create formatters and add it to handlers
c_format = logging.Formatter('%(name)s - %(levelname)s - %(message)s')
f_format = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
c_handler.setFormatter(c_format)
f_handler.setFormatter(f_format)

# Add handlers to the logger
logger.addHandler(c_handler)
logger.addHandler(f_handler)

logger.warning('This is a warning')
logger.error('This is an error')
logger.info('This is an info')
logger.debug('This is a debug')

您可以找到更多信息here

Python 即使处理程序级别设置为调试，记录器也不显示调试级别消息

Python logger not showing DEBUG level messages even though handler level is set to debug

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python-logging