Logging Handlers Empty - Why Logging TimeRoatingFileHandler doesn't work

log-rotation, logging, logrotate, python, windows

Solution

It seems you need to correctly get the root logger:

logger = logging.getLogger(__name__)
handlers = logger.handlers[:]
print('module {}'.format(handlers))
print('module {}'.format(logger.hasHandlers()))

logger = logging.getLogger('root')
handlers = logger.handlers[:]
print('root {}'.format(handlers))
print('root {}'.format(logger.hasHandlers()))

logger = logging.getLogger()
handlers = logger.handlers[:]
print('blank {}'.format(handlers))
print('blank {}'.format(logger.hasHandlers()))

output:

module []

module True

root []

root True

blank `[<logging.handlers.RotatingFileHandler object at 0x108d82898>, <logging.StreamHandler object at 0x108d826d8>]`

blank True

Problem

So I do logging.config.fileConfig to setup my logging from a file config that has console and file handler. Then I do logging.getLogger(name) to get my logger and log. At certain times I want the filehandler's filename to change i.e. log rotate (I can't use time rotator because of some issues with Windows platform) so to do that I call logger.handlers - it shows an empty list, so I cant close them!! However when I step through the debugger, its clearly not empty (well of course without it I wouldn't be able to log right) Not sure whats going on here, any gotchas that I'm missing? Appreciate any help. Thanks.

Original source