如何只记录某个levelname python logging

Question

[loggers]
keys=root

[handlers]
keys=consoleHandler,errorHandler,debugHandler

[formatters]
keys=errorFormatter,debugFormatter

[logger_root]
level=DEBUG
handlers=consoleHandler,errorHandler,debugHandler
propagate=0

[handler_consoleHandler]
class=StreamHandler
level=DEBUG
formatter=debugFormatter
args=(sys.stdout,)

[handler_errorHandler]
class=FileHandler
level=ERROR
formatter=errorFormatter
args=('errors.log',)

[handler_debugHandler]
class=FileHandler
level=DEBUG
formatter=debugFormatter
args=('debugs.log',)

[formatter_errorFormatter]
style={
format=
    {asctime} - {name} - {levelname} - line {lineno} - {message}
datefmt=%d/%m/%y - %H:%M:%S

[formatter_debugFormatter]
style={
format={asctime} - {name} - {levelname} - {message}
datefmt=%d/%m/%y - %H:%M:%S

如果我有一个像上面那样的配置文件，我如何访问 debugHandler 以便我可以像 debugHandler.addFilter(my_custom_filter) 那样做？

我实际上是在尝试将 DEBUG 条消息发送到 debugs.log，将 ERROR 条消息发送到 errors.log，但目前 [=16] =] 消息也被发送到 debugs.log 我不想要的。现在，基于，这可以通过过滤器实现，但为了添加过滤器，我需要一个 logging.Handler 对象，但我不知道如何获得一个。

提前致谢:~)

Answer 1

是的，您需要在 debug_handler 上添加过滤器，但是您不能通过 fileConfig 添加过滤器。

来自文档：

The fileConfig() API is older than the dictConfig() API and does not provide functionality to cover certain aspects of logging. For example, you cannot configure Filter objects, which provide for filtering of messages beyond simple integer levels, using fileConfig(). If you need to have instances of Filter in your logging configuration, you will need to use dictConfig(). Note that future enhancements to configuration functionality will be added to dictConfig(), so it’s worth considering transitioning to this newer API when it’s convenient to do so.

因此请考虑使用 dictConfig（您没有任何理由不切换到 dictConfig，无论您的配置如何，因为它更好、更新、更灵活，而且一个将添加所有未来好东西的地方）。

所以你的配置，转换到 dictConfig 看起来像这样（可以按原样粘贴和测试）：

import logging
from logging import config

class FileFilter:
    """Allow only LogRecords whose severity levels are below ERROR."""

    def __call__(self, log):
        if log.levelno < logging.ERROR:
            return 1
        else:
            return 0


logging_config = {
    'version': 1,
    'formatters': {
        'error_formatter': {
            'format': '{asctime} - {name} - {levelname} - line {lineno} - {message}',
            'style': '{',
            'datefmt': '%d/%m/%y - %H:%M:%S',
        },
        'debug_formatter': {
            'format': '{asctime} - {name} - {levelname} - {message}',
            'style': '{',
            'datefmt': '%d/%m/%y - %H:%M:%S',
        },
    },
    'filters': {
        'file_filter': {
            '()': FileFilter,
        },
    },
    'handlers': {
        'console_handler': {
            'class': 'logging.StreamHandler',
            'formatter': 'debug_formatter',
        },
        'error_handler': {
            'class': 'logging.FileHandler',
            'formatter': 'debug_formatter',
            'level': 'ERROR',
            'filename': 'errors.log',
        },
        'debug_handler': {
            'class': 'logging.FileHandler',
            'formatter': 'debug_formatter',
            'filters': ['file_filter'],
            'filename': 'debug.log',
        },
    },
    'root': {
        'level': 'DEBUG',
        'handlers': ['console_handler', 'error_handler', 'debug_handler'],
    },
}

config.dictConfig(logging_config)

logger = logging.getLogger(__name__)

# these get logged to the console and only to the debugs.log file
# if you want just the debug messages logged to the file, adjust the filter
logger.debug('this is a debug message')
logger.info('this is an info message')
logger.warning('this is a warning message')

# this get logged to the console and only to the errors.log file
logger.error('this is an error message')
logger.critical('this is a critical message')

将输出：

27/09/19 - 07:52:44 - __main__ - DEBUG - this is a debug message  # also to debug.log
27/09/19 - 07:52:44 - __main__ - INFO - this is an info message  # also to debug.log
27/09/19 - 07:52:44 - __main__ - WARNING - this is a warning message  # also to debug.log
27/09/19 - 07:52:44 - __main__ - ERROR - this is an error message  # also to errors.log but not to debug.log
27/09/19 - 07:52:44 - __main__ - CRITICAL - this is a critical message  # also to errors.log but not to debug.log

如果您出于某种神秘原因（我看不到任何原因）坚持使用旧的 API、fileConfig，请参阅 this answer，它使用自定义格式化程序，实现同样的事情，没有过滤器。

如何只记录某个levelname python logging

How to only log a certain levelname python logging

python

python-3.x

python-logging