Tukukkk

I've written an init function to configure the python logging module to log to a file and the console. I want to limit the log file size using the RotatingFileHandler. The code below doesn't cause any errors and does everything I want, except it doesn't rotate the logs. I set a low file size to test things out.

How can I configure to use rotating logs and the console with different formats like below?

import logging, logging.handlers



LOG_LEVEL = logging.DEBUG

CONSOLE_LEVEL = logging.DEBUG





def init_logger(fullpath, console_level=CONSOLE_LEVEL, log_level=LOG_LEVEL):

    """

    Setup the logger object



    Args:

        fullpath (str): full path to the log file

    """

    logging.basicConfig(level=LOG_LEVEL,

                format='%(asctime)s %(threadName)-10s %(name)-12s % 

                (levelname)-8s %(message)s',

                datefmt='%m-%d-%y %H:%M:%S',

                filename=fullpath,

                filemode='w')



    _logger = logging.getLogger('_root')

    _logger.setLevel(log_level)



    log_handler = logging.handlers.RotatingFileHandler(filename=fullpath, 

        maxBytes=50, backupCount=10)

    log_handler.setLevel(log_level)

    _logger.addHandler(log_handler)



    console = logging.StreamHandler()

    console.setLevel(console_level)

    # set a format which is simpler for console use

    formatter = logging.Formatter('%(name)-12s: %(levelname)-8s % 

       (message)s')

    # tell the handler to use this format

    console.setFormatter(formatter)

    # add the handler to the root logger

    logging.getLogger('').addHandler(console)

    logging.debug("Creating log file")

This is your logging's structure:

---root <- I mean real root, which you will get from logging.getLogger([""])

---NormalFileHandler <- Configged by logging.basicConfig, this handler won't rotate file.

---StreamHandler

------_root <- Your root logger, although I don't understand why you want this.

------RotatingFileHandler <- This one will rotate file.

And then you use logging.debug("Creating log file"), which is the same as calling debug on root logger: logging.getLogger().debug(...). So this log passed to StreamHandler and NormalFileHandler.

That's why you see the file isn't got rotated.

The correct configuration should be:

def init_logger(fullpath, console_level=CONSOLE_LEVEL, log_level=LOG_LEVEL):

    """

    Setup the logger object



    Args:

        fullpath (str): full path to the log file

    """

    logger = logging.getLogger('YourLogger')

    logger.setLevel(log_level)



    log_handler = logging.handlers.RotatingFileHandler(filename=fullpath, 

        maxBytes=50, backupCount=10)

    log_handler.setLevel(log_level)

    formatter = logging.Formatter('%(asctime)s %(threadName)-10s %(name)-12s % 

                (levelname)-8s %(message)s')

    log_handler.setFormatter(formatter)

    logger.addHandler(log_handler)



    console = logging.StreamHandler()

    console.setLevel(console_level)

    formatter = logging.Formatter('%(name)-12s: %(levelname)-8s % 

       (message)s')

    console.setFormatter(formatter)

    logger.addHandler(console)  # Or you can add it to root logger, but it is not recommended, you should use your own logger instead of root logger. Or it will cause some problems.

    logger.debug("Creating log file")

And then when you want to use logger, you should use:

logger = logging.getLogger('YourLogger')

logger.info(...)

logger.debug(...)