如何将自定义日志级别添加到Python的日志工具中

@ Eric S.

Eric S的回答很好,但我通过实验了解到,这将始终导致打印在新调试级别记录的消息,而不管日志级别设置为什么。因此,如果将新的级别编号设为9,如果调用setlevel(50),则会错误地打印较低级别的消息。为了防止这种情况发生,您需要在“debugv”函数中使用另一行来检查是否实际启用了相关的日志级别。

修复了检查日志记录级别是否已启用的示例:

import logging
DEBUG_LEVELV_NUM = 9 
logging.addLevelName(DEBUG_LEVELV_NUM, "DEBUGV")
def debugv(self, message, *args, **kws):
    if self.isEnabledFor(DEBUG_LEVELV_NUM):
        # Yes, logger takes its '*args' as 'args'.
        self._log(DEBUG_LEVELV_NUM, message, args, **kws) 
logging.Logger.debugv = debugv

如果你看代码 class Logger 在里面 logging.__init__.py 对于Python2.7,这是所有标准日志函数所做的工作(关键的,.debug等)。

很明显我不能回复别人的答案,因为他们缺乏声誉…希望埃里克看到这一点会更新他的帖子。=)

我得到了“避免看到lambda”的答案,并且必须修改在“我的日志”级别添加日志的位置。我也看到了保罗的问题,“我认为这行不通。你不需要记录器作为日志中的第一个参数吗?这对我有用

import logging
DEBUG_LEVELV_NUM = 9 
logging.addLevelName(DEBUG_LEVELV_NUM, "DEBUGV")
def debugv(self, message, *args, **kws):
    # Yes, logger takes its '*args' as 'args'.
    self._log(DEBUG_LEVELV_NUM, message, args, **kws) 
logging.Logger.debugv = debugv

这个问题很古老,但我只是处理了同一个话题,发现了一种类似于前面提到的,对我来说似乎更清楚的方法。这是在3.4上测试的,所以我不确定使用的方法是否存在于旧版本中:

from logging import getLoggerClass, addLevelName, setLoggerClass, NOTSET

VERBOSE = 5

class MyLogger(getLoggerClass()):
    def __init__(self, name, level=NOTSET):
        super().__init__(name, level)

        addLevelName(VERBOSE, "VERBOSE")

    def verbose(self, msg, *args, **kwargs):
        if self.isEnabledFor(VERBOSE):
            self._log(VERBOSE, msg, args, **kwargs)

setLoggerClass(MyLogger)

将所有现有答案与一系列使用经验结合起来,我认为我已经列出了所有需要做的事情,以确保新级别的完全无缝使用。下面的步骤假设您正在添加一个新级别 TRACE 有价值 logging.DEBUG - 5 == 5 :

1. logging.addLevelName(logging.DEBUG - 5, 'TRACE') 需要调用以在内部注册新级别,以便可以通过名称引用它。
2. 需要将新级别作为属性添加到 logging 为了保持一致性: logging.TRACE = logging.DEBUG - 5 .
3. 称之为方法 trace 需要添加到 登录中 模块。它应该表现得像 debug , info 等。
4. 调用的方法 追踪 需要添加到当前配置的记录器类中。因为这不是100%的保证 logging.Logger 使用 logging.getLoggerClass() 相反。

所有步骤如下所示:

def addLoggingLevel(levelName, levelNum, methodName=None):
    """
    Comprehensively adds a new logging level to the `logging` module and the
    currently configured logging class.

    `levelName` becomes an attribute of the `logging` module with the value
    `levelNum`. `methodName` becomes a convenience method for both `logging`
    itself and the class returned by `logging.getLoggerClass()` (usually just
    `logging.Logger`). If `methodName` is not specified, `levelName.lower()` is
    used.

    To avoid accidental clobberings of existing attributes, this method will
    raise an `AttributeError` if the level name is already an attribute of the
    `logging` module or if the method name is already present 

    Example
    -------
    >>> addLoggingLevel('TRACE', logging.DEBUG - 5)
    >>> logging.getLogger(__name__).setLevel("TRACE")
    >>> logging.getLogger(__name__).trace('that worked')
    >>> logging.trace('so did this')
    >>> logging.TRACE
    5

    """
    if not methodName:
        methodName = levelName.lower()

    if hasattr(logging, levelName):
       raise AttributeError('{} already defined in logging module'.format(levelName))
    if hasattr(logging, methodName):
       raise AttributeError('{} already defined in logging module'.format(methodName))
    if hasattr(logging.getLoggerClass(), methodName):
       raise AttributeError('{} already defined in logger class'.format(methodName))

    # This method was inspired by the answers to Stack Overflow post
    # http://stackoverflow.com/q/2183233/2988730, especially
    # http://stackoverflow.com/a/13638084/2988730
    def logForLevel(self, message, *args, **kwargs):
        if self.isEnabledFor(levelNum):
            self._log(levelNum, message, args, **kwargs)
    def logToRoot(message, *args, **kwargs):
        logging.log(levelNum, message, *args, **kwargs)

    logging.addLevelName(levelNum, levelName)
    setattr(logging, levelName, levelNum)
    setattr(logging.getLoggerClass(), methodName, logForLevel)
    setattr(logging, methodName, logToRoot)

是谁开始使用内部方法的坏做法的?( self._log )为什么每个答案都是基于这个?!将要使用的pythonic解决方案 self.log 相反,这样你就不必乱动任何内部的东西:

import logging

SUBDEBUG = 5
logging.addLevelName(SUBDEBUG, 'SUBDEBUG')

def subdebug(self, message, *args, **kws):
    self.log(SUBDEBUG, message, *args, **kws) 
logging.Logger.subdebug = subdebug

logging.basicConfig()
l = logging.getLogger()
l.setLevel(SUBDEBUG)
l.subdebug('test')
l.setLevel(logging.DEBUG)
l.subdebug('test')

我发现为传递logger()函数的logger对象创建新属性更容易。我认为logger模块提供addLevelName()和log()是因为这个原因。因此不需要子类或新方法。

import logging

@property
def log(obj):
    logging.addLevelName(5, 'TRACE')
    myLogger = logging.getLogger(obj.__class__.__name__)
    setattr(myLogger, 'trace', lambda *args: myLogger.log(5, *args))
    return myLogger

现在

mylogger.trace('This is a trace message')

应该按预期工作。

我想你得把 Logger 类并添加名为 trace 这基本上就是 Logger.log 水平低于 DEBUG . 我没试过,但这就是 docs indicate .

创建自定义记录器的提示:

1. 不要使用 _log 使用 log (你不必检查 isEnabledFor )
2. 日志模块应该是自定义记录器的一个创建实例,因为它在 getLogger ,因此您需要通过设置类 setLoggerClass
3. 你不需要定义 __init__ 对于记录器,如果没有存储任何内容,则初始化

# Lower than debug which is 10
TRACE = 5
class MyLogger(logging.Logger):
    def trace(self, msg, *args, **kwargs):
        self.log(TRACE, msg, *args, **kwargs)

调用此记录器时,请使用 setLoggerClass(MyLogger) 使其成为默认记录器 获得记录器

logging.setLoggerClass(MyLogger)
log = logging.getLogger(__name__)
# ...
log.trace("something specific")

你需要 setFormatter , setHandler ,和 setLevel(TRACE) 上 handler 以及关于 日志 它本身实际上就是这个低级别的跟踪

这对我很有用:

import logging
logging.basicConfig(
    format='  %(levelname)-8.8s %(funcName)s: %(message)s',
)
logging.NOTE = 32  # positive yet important
logging.addLevelName(logging.NOTE, 'NOTE')      # new level
logging.addLevelName(logging.CRITICAL, 'FATAL') # rename existing

log = logging.getLogger(__name__)
log.note = lambda msg, *args: log._log(logging.NOTE, msg, args)
log.note('school\'s out for summer! %s', 'dude')
log.fatal('file not found.')

lambda/funcname问题已通过logger修复。_log as@marqueed指出。我认为使用lambda看起来有点干净,但缺点是它不能接受关键字参数。我自己从来没有用过,所以没什么大不了的。

  NOTE     setup: school's out for summer! dude
  FATAL    setup: file not found.

以我的经验来看,这是全面的解决方案——手术的问题……要避免将“lambda”视为消息发出的函数,请更深入:

MY_LEVEL_NUM = 25
logging.addLevelName(MY_LEVEL_NUM, "MY_LEVEL_NAME")
def log_at_my_log_level(self, message, *args, **kws):
    # Yes, logger takes its '*args' as 'args'.
    self._log(MY_LEVEL_NUM, message, args, **kws)
logger.log_at_my_log_level = log_at_my_log_level

我从未尝试过使用独立的logger类,但我认为基本思想是相同的(使用日志)。

添加MAD物理学家示例以获得正确的文件名和行号:

def logToRoot(message, *args, **kwargs):
    if logging.root.isEnabledFor(levelNum):
        logging.root._log(levelNum, message, args, **kwargs)

作为向logger类添加额外方法的替代方法,我建议使用 Logger.log(level, msg) 方法。

import logging

TRACE = 5
logging.addLevelName(TRACE, 'TRACE')
FORMAT = '%(levelname)s:%(name)s:%(lineno)d:%(message)s'


logging.basicConfig(format=FORMAT)
l = logging.getLogger()
l.setLevel(TRACE)
l.log(TRACE, 'trace message')
l.setLevel(logging.DEBUG)
l.log(TRACE, 'disabled trace message')

我很困惑;至少对于python 3.5来说,它是有效的:

import logging


TRACE = 5
"""more detail than debug"""

logging.basicConfig()
logging.addLevelName(TRACE,"TRACE")
logger = logging.getLogger('')
logger.debug("n")
logger.setLevel(logging.DEBUG)
logger.debug("y1")
logger.log(TRACE,"n")
logger.setLevel(TRACE)
logger.log(TRACE,"y2")

输出:

调试:根:Y1

痕迹:根:Y2

基于固定答案, 我写了一个自动创建新日志级别的小方法

def set_custom_logging_levels(config={}):
    """
        Assign custom levels for logging
            config: is a dict, like
            {
                'EVENT_NAME': EVENT_LEVEL_NUM,
            }
        EVENT_LEVEL_NUM can't be like already has logging module
        logging.DEBUG       = 10
        logging.INFO        = 20
        logging.WARNING     = 30
        logging.ERROR       = 40
        logging.CRITICAL    = 50
    """
    assert isinstance(config, dict), "Configuration must be a dict"

    def get_level_func(level_name, level_num):
        def _blank(self, message, *args, **kws):
            if self.isEnabledFor(level_num):
                # Yes, logger takes its '*args' as 'args'.
                self._log(level_num, message, args, **kws) 
        _blank.__name__ = level_name.lower()
        return _blank

    for level_name, level_num in config.items():
        logging.addLevelName(level_num, level_name.upper())
        setattr(logging.Logger, level_name.lower(), get_level_func(level_name, level_num))

配置可能会这样:

new_log_levels = {
    # level_num is in logging.INFO section, that's why it 21, 22, etc..
    "FOO":      21,
    "BAR":      22,
}

如果有人想要一种自动方式动态地向日志模块(或其副本)添加新的日志级别,我已经创建了这个函数,扩展了@pfa的答案:

def add_level(log_name,custom_log_module=None,log_num=None,
                log_call=None,
                   lower_than=None, higher_than=None, same_as=None,
              verbose=True):
    '''
    Function to dynamically add a new log level to a given custom logging module.
    <custom_log_module>: the logging module. If not provided, then a copy of
        <logging> module is used
    <log_name>: the logging level name
    <log_num>: the logging level num. If not provided, then function checks
        <lower_than>,<higher_than> and <same_as>, at the order mentioned.
        One of those three parameters must hold a string of an already existent
        logging level name.
    In case a level is overwritten and <verbose> is True, then a message in WARNING
        level of the custom logging module is established.
    '''
    if custom_log_module is None:
        import imp
        custom_log_module = imp.load_module('custom_log_module',
                                            *imp.find_module('logging'))
    log_name = log_name.upper()
    def cust_log(par, message, *args, **kws):
        # Yes, logger takes its '*args' as 'args'.
        if par.isEnabledFor(log_num):
            par._log(log_num, message, args, **kws)
    available_level_nums = [key for key in custom_log_module._levelNames
                            if isinstance(key,int)]

    available_levels = {key:custom_log_module._levelNames[key]
                             for key in custom_log_module._levelNames
                            if isinstance(key,str)}
    if log_num is None:
        try:
            if lower_than is not None:
                log_num = available_levels[lower_than]-1
            elif higher_than is not None:
                log_num = available_levels[higher_than]+1
            elif same_as is not None:
                log_num = available_levels[higher_than]
            else:
                raise Exception('Infomation about the '+
                                'log_num should be provided')
        except KeyError:
            raise Exception('Non existent logging level name')
    if log_num in available_level_nums and verbose:
        custom_log_module.warn('Changing ' +
                                  custom_log_module._levelNames[log_num] +
                                  ' to '+log_name)
    custom_log_module.addLevelName(log_num, log_name)

    if log_call is None:
        log_call = log_name.lower()

    setattr(custom_log_module.Logger, log_call, cust_log)
    return custom_log_module