Determining if root logger is set to DEBUG level in Python?

问题

If I set the logging module to DEBUG with a command line parameter like this:

if (opt["log"] == "debug"):
  logging.basicConfig(level=logging.DEBUG)

How can I later tell if the logger was set to DEBUG? I'm writing a decorator that will time a function if True flag is passed to it, and if no flag is given, it defaults to printing timing information when the root logger is set to DEBUG.

回答1:

logging.getLogger().getEffectiveLevel()

logging.getLogger() without arguments gets the root level logger.

http://docs.python.org/library/logging.html#logging.Logger.getEffectiveLevel

回答2:

Actually, there's one better: use the code logging.getLogger().isEnabledFor(logging.DEBUG). I found it while trying to understand what to do with the result of getEffectiveLevel().

Below is the code that the logging module itself uses.

def getEffectiveLevel(self):
    """
    Get the effective level for this logger.

    Loop through this logger and its parents in the blogger hierarchy,
    looking for a non-zero logging level. Return the first one found. 
    """
    logger = self
    while logger:
        if logger.level:
            return logger.level
        logger = logger.parent
    return NOTSET

def isEnabledFor(self, level):
    """
    Is this logger enabled for level ‘level’?
    """
    if self.manager.disable >= level:
        return 0
    return level >= self.getEffectiveLevel()

回答3:

Just

logging.getLogger().level == logging.DEBUG

来源：https://stackoverflow.com/questions/1987468/determining-if-root-logger-is-set-to-debug-level-in-python