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
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
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()
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)
这里有一些非常好的答案,但显然没有考虑太多最简单的答案(只从无穷开始)。
root_logger = logging.getLogger()
root_logger.disabled = True
这将禁用根日志记录器,从而禁用所有其他日志记录器。 我还没有真正测试过,但它应该是最快的。
从python 2.7的日志代码中,我看到了这一点
def handle(self, record):
"""
Call the handlers for the specified record.
This method is used for unpickled records received from a socket, as
well as those created locally. Logger-level filtering is applied.
"""
if (not self.disabled) and self.filter(record):
self.callHandlers(record)
这意味着当它被禁用时,不会调用任何处理程序,并且它应该比过滤到一个非常高的值或设置一个no-op处理程序更有效。
(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)
您可以更改特定处理程序的调试模式级别,而不是完全禁用它。
因此,如果你有一个情况,你想停止调试模式的控制台,但你仍然需要保持其他级别,如错误。你可以像下面这样做
# create logger
logger = logging.getLogger(__name__)
def enableConsoleDebug (debug = False):
#Set level to logging.DEBUG to see CRITICAL, ERROR, WARNING, INFO and DEBUG statements
#Set level to logging.ERROR to see the CRITICAL & ERROR statements only
logger.setLevel(logging.DEBUG)
debugLevel = logging.ERROR
if debug:
debugLevel = logging.DEBUG
for handler in logger.handlers:
if type(handler) is logging.StreamHandler:
handler.setLevel (debugLevel)