149

我想为我的应用程序设置 loglevel TRACE (5),因为我认为这debug()还不够。另外log(5, msg)不是我想要的。如何将自定义日志级别添加到 Python 记录器?

我有mylogger.py以下内容:

import logging

@property
def log(obj):
    myLogger = logging.getLogger(obj.__class__.__name__)
    return myLogger

在我的代码中,我以下列方式使用它:

class ExampleClass(object):
    from mylogger import log

    def __init__(self):
        '''The constructor with the logger'''
        self.log.debug("Init runs")

现在我想打电话self.log.trace("foo bar")

编辑(2016 年 12 月 8 日):我将接受的答案更改为pfa,即恕我直言,这是基于 Eric S.

4

17 回答 17

207

对于 2022 年及以后阅读的人:您可能应该在此处查看当前评分最高的答案:https ://stackoverflow.com/a/35804945/1691778

我的原始答案如下。

--

@埃里克·S。

Eric S. 的回答非常好,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——无论日志级别设置为什么。因此,如果您创建一个新的级别编号9,如果您调用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”函数中添加另一行来检查是否实际启用了相关的日志记录级别。

修复了检查日志级别是否启用的示例:

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

如果您查看 Python 2.7 的class Loggerin代码logging.__init__.py,这就是所有标准日志函数(.critical、.debug 等)所做的。

由于缺乏声誉,我显然无法回复其他人的答案......希望埃里克看到这个后会更新他的帖子。=)

于 2012-11-30T02:17:06.237 回答
93

结合所有现有答案和大量使用经验,我想我已经列出了所有需要做的事情,以确保完全无缝地使用新关卡。下面的步骤假设您正在添加一个新TRACE的 value级别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. 为了保持一致性,需要将新级别作为属性添加到logging自身:logging.TRACE = logging.DEBUG - 5.
  3. trace需要将调用的方法添加到logging模块中。它的行为应该像debug,info等。
  4. 需要将调用的方法trace添加到当前配置的记录器类中。由于这不是 100% 保证的logging.Logger,请logging.getLoggerClass()改用。

以下方法说明了所有步骤:

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)

您可以在我维护的实用程序库haggis中找到更详细的实现。该功能haggis.logs.add_logging_level是此答案的更易于生产的实现。

于 2016-03-04T19:54:20.290 回答
68

避免看到“lambda”答案,不得不修改log_at_my_log_level添加的位置。我也看到了保罗所做的问题——我认为这行不通。你不需要 logger 作为第一个参数log_at_my_log_level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
于 2012-08-02T20:08:51.810 回答
43

这个问题相当老了,但我只是处理了同样的话题,并找到了一种与已经提到的方法相似的方法,这对我来说似乎更干净一些。这是在 3.4 上测试的,所以我不确定旧版本中是否存在使用的方法:

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)
于 2014-03-23T02:07:19.073 回答
25

虽然我们已经有了很多正确的答案,但在我看来,以下内容更符合 Python 风格:

import logging

from functools import partial, partialmethod

logging.TRACE = 5
logging.addLevelName(logging.TRACE, 'TRACE')
logging.Logger.trace = partialmethod(logging.Logger.log, logging.TRACE)
logging.trace = partial(logging.log, logging.TRACE)

如果要mypy在代码上使用,建议添加# type: ignore以禁止添加属性的警告。

于 2019-03-21T08:57:26.157 回答
20

谁开始使用内部方法(self._log)的不良做法,为什么每个答案都基于此?!pythonic 解决方案将改为使用self.log,因此您不必弄乱任何内部的东西:

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')
于 2013-06-06T06:27:25.007 回答
9

我认为您必须对该类进行子Logger类化并添加一个名为的方法,该方法trace基本上Logger.log以低于DEBUG. 我没有尝试过,但这就是文档所指出的。

于 2010-02-02T10:27:50.613 回答
8

我发现为传递 log() 函数的记录器对象创建新属性更容易。我认为 logger 模块正是出于这个原因提供了 addLevelName() 和 log() 。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。

于 2010-05-12T13:13:41.660 回答
6

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. 日志记录模块应该是自定义记录器的一个创建实例,因为它有一些魔力getLogger,所以你需要通过设置类setLoggerClass
  3. __init__如果您不存储任何内容,则无需为记录器、类定义
# 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,请将此记录器setLoggerClass(MyLogger)设为默认记录器getLogger

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

您将需要setFormatter, setHandler, and setLevel(TRACE)on thehandler和 onlog来实际设置这个低级跟踪

于 2016-08-17T22:51:09.140 回答
3

这对我有用:

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.')

正如@marqueed 指出的那样, logger._log 解决了 lambda/funcName 问题。我认为使用 lambda 看起来更干净一些,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。

  注意设置:学校放暑假了!老兄
  致命设置:找不到文件。
于 2012-08-21T06:24:39.877 回答
2

以我的经验,这是操作问题的完整解决方案......为了避免将“lambda”视为发出消息的函数,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记录器类,但我认为基本思想是相同的(使用 _log)。

于 2011-09-22T05:55:14.350 回答
2

除了 Mad Physicists 示例以获取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)
于 2016-11-21T12:17:40.703 回答
1

基于固定的答案,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))

config 可能是这样的:

new_log_levels = {
    # level_num is in logging.INFO section, that's why it 21, 22, etc..
    "FOO":      21,
    "BAR":      22,
}
于 2019-01-11T13:36:02.857 回答
1

有人可能想做,根级别的自定义日志记录;并避免使用 logging.get_logger(''):

import logging
from datetime import datetime
c_now=datetime.now()
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] :: %(message)s",
    handlers=[
        logging.StreamHandler(),
        logging.FileHandler("../logs/log_file_{}-{}-{}-{}.log".format(c_now.year,c_now.month,c_now.day,c_now.hour))
    ]
)
DEBUG_LEVELV_NUM = 99 
logging.addLevelName(DEBUG_LEVELV_NUM, "CUSTOM")
def custom_level(message, *args, **kws):
    logging.Logger._log(logging.root,DEBUG_LEVELV_NUM, message, args, **kws) 
logging.custom_level = custom_level
# --- --- --- --- 
logging.custom_level("Waka")
于 2021-08-31T16:41:53.970 回答
0

作为向 Logger 类添加额外方法的替代方法,我建议使用该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')
于 2013-10-30T13:40:33.977 回答
0

我很困惑; 至少使用 python 3.5,它可以正常工作:

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

跟踪:根:y2

于 2018-02-24T13:49:53.837 回答
-3

如果有人想要一种自动化的方式来动态地将新的日志记录级别添加到日志记录模块(或它的副本),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
于 2017-04-08T16:28:39.497 回答