如何在Python中禁用标准错误流的日志记录?这行不通:

import logging

logger = logging.getLogger()
logger.removeHandler(sys.stderr)
logger.warning('foobar')  # emits 'foobar' on sys.stderr

当前回答

日志有以下结构:

loggers are arranged according to a namespace hierarchy with dot separators; each logger has a level (logging.WARNING by default for the root logger and logging.NOTSET by default for non-root loggers) and an effective level (the effective level of the parent logger for non-root loggers with a level logging.NOTSET and the level of the logger otherwise); each logger has a list of filters; each logger has a list of handlers; each handler has a level (logging.NOTSET by default); each handler has a list of filters.

日志记录有以下过程(由流程图表示):

因此,要禁用特定的记录器,您可以采用以下策略之一:

Set the level of the logger to logging.CRITICAL + 1. Using the main API: import logging logger = logging.getLogger("foo") logger.setLevel(logging.CRITICAL + 1) Using the config API: import logging.config logging.config.dictConfig({ "version": 1, "loggers": { "foo": { "level": logging.CRITICAL + 1 } } }) Add a filter lambda record: False to the logger. Using the main API: import logging logger = logging.getLogger("foo") logger.addFilter(lambda record: False) Using the config API: import logging.config logging.config.dictConfig({ "version": 1, "filters": { "all": { "()": lambda: (lambda record: False) } }, "loggers": { "foo": { "filters": ["all"] } } }) Remove the existing handlers of the logger, add a handler logging.NullHandler() to the logger (to prevent events from being handled by the handler logging.lastResort which is a logging.StreamHandler using the current stream sys.stderr and a level logging.WARNING) and set the attribute propagate of the logger to False (to prevent events from being handled by the handlers of the ancestor loggers of the logger). Using the main API: import logging logger = logging.getLogger("foo") for handler in logger.handlers.copy(): try: logger.removeHandler(handler) except ValueError: # in case another thread has already removed it pass logger.addHandler(logging.NullHandler()) logger.propagate = False Using the config API: import logging.config logging.config.dictConfig({ "version": 1, "handlers": { "null": { "class": "logging.NullHandler" } }, "loggers": { "foo": { "handlers": ["null"], "propagate": False } } })

警告。策略1和2只阻止记录器记录的事件被记录器的处理程序及其祖先记录器发出,策略3还阻止记录器的后代记录器记录的事件(例如logging.getLogger("foo.bar"))被记录器的处理程序及其祖先记录器发出。

请注意。—将日志记录器禁用的属性设置为True不是另一种策略,因为它不是公共API的一部分(参见https://bugs.python.org/issue36318):

import logging

logger = logging.getLogger("foo")
logger.disabled = True  # DO NOT DO THIS

其他回答

不需要转移标准输出。这里有一个更好的方法:

import logging
class MyLogHandler(logging.Handler):
    def emit(self, record):
        pass

logging.getLogger().addHandler(MyLogHandler())

一个更简单的方法是:

logging.getLogger().setLevel(100)

子类化你想要暂时禁用的处理程序:

class ToggledHandler(logging.StreamHandler):
"""A handler one can turn on and off"""

def __init__(self, args, kwargs):
    super(ToggledHandler, self).__init__(*args, **kwargs)
    self.enabled = True  # enabled by default

def enable(self):
    """enables"""
    self.enabled = True

def disable(self):
    """disables"""
    self.enabled = False

def emit(self, record):
    """emits, if enabled"""
    if self.enabled:
        # this is taken from the super's emit, implement your own
        try:
            msg = self.format(record)
            stream = self.stream
            stream.write(msg)
            stream.write(self.terminator)
            self.flush()
        except Exception:
            self.handleError(record)

通过名称查找处理程序非常简单:

_handler = [x for x in logging.getLogger('').handlers if x.name == your_handler_name]
if len(_handler) == 1:
    _handler = _handler[0]
else:
    raise Exception('Expected one handler but found {}'.format(len(_handler))

一旦发现:

_handler.disable()
doStuff()
_handler.enable()

我找到了一个解决方案:

logger = logging.getLogger('my-logger')
logger.propagate = False
# now if you use logger it will not log to console.

这将防止日志被发送到包含控制台日志的上层记录器。

(早就死了的问题,但对未来的搜索者来说)

更接近最初海报的代码/意图,这适用于我在python 2.6下

#!/usr/bin/python
import logging

logger = logging.getLogger() # this gets the root logger

lhStdout = logger.handlers[0]  # stdout is the only handler initially

# ... here I add my own handlers 
f = open("/tmp/debug","w")          # example handler
lh = logging.StreamHandler(f)
logger.addHandler(lh)

logger.removeHandler(lhStdout)

logger.debug("bla bla")

我必须解决的问题是在添加一个新的stdout处理程序后删除它;如果没有处理程序,记录器代码将自动重新添加标准输出。

IndexOutOfBound修复:如果你得到一个IndexOutOfBound错误,而实例化lhStdout,移动实例化后添加你的文件处理程序,即。

...
logger.addHandler(lh)

lhStdout = logger.handlers[0]
logger.removeHandler(lhStdout)

这不是100%的解决方案,但这里没有一个答案解决了我的问题。我有自定义的日志模块,根据严重程度输出彩色文本。我需要禁用stdout输出,因为它复制了我的日志。我对将关键日志输出到控制台很满意,因为我几乎不使用它。我没有测试它是否为stderr,因为我没有在日志中使用它,但它应该与stdout的工作方式相同。它将CRITICAL设置为仅针对stdout的最小严重程度(如果请求则为stderr)。

logger = logging.getLogger()
logger.setLevel(logging.DEBUG)

# disable terminal output - it is handled by this module
stdout_handler = logging.StreamHandler(sys.stdout)

# set terminal output to critical only - won't output lower levels
stdout_handler.setLevel(logging.CRITICAL)

# add adjusted stream handler
logger.addHandler(stdout_handler)