Python multiple loggers not working. How to configure multiple loggers with different levels?

Question

I am trying to configure two loggers, one logger is for INFO level, and the other logger is for DEBUG level. I would like DEBUG content to only go to my log file, and I would like the INFO content to go both a log file and to the console. Please see the below code. Nothing is being written into my files and nothing is being displayed in the console.

logFileDir = os.path.join(os.getcwd(), '.logs')
if not os.path.exists(logFileDir):
    os.mkdir(logFileDir)
infoLogFileDir = os.path.join(logFileDir, 'INFO')
if not os.path.exists(infoLogFileDir):
    os.mkdir(infoLogFileDir)
debugLogFileDir = os.path.join(logFileDir, 'DEBUG')
if not os.path.exists(debugLogFileDir):
    os.mkdir(debugLogFileDir)
LOG_FORMAT = ("%(asctime)s [%(levelname)s]: %(message)s in %(pathname)s:%(lineno)d")

#DEBUG LOGGER
debugLogFileName = os.path.join(debugLogFileDir, 'EFDebugLog.log')
debugLogger = logging.getLogger("debugLogger")
debugLogger.setLevel(logging.DEBUG)
debugHandler = logging.handlers.RotatingFileHandler(filename=debugLogFileName,maxBytes=5000000, backupCount=100)
debugHandler.setLevel(logging.DEBUG)
debugHandler.setFormatter(Formatter(LOG_FORMAT))
debugLogger.addHandler(debugHandler)

#INFO LOGGER
infoLogFileName = os.path.join(infoLogFileDir, 'EFInfoLog.log')
infoLogger = logging.getLogger("infoLogger")
infoLogger.setLevel(logging.INFO)
infoHandler = logging.handlers.RotatingFileHandler(filename=infoLogFileName,maxBytes=5000000, backupCount=100)
infoHandler.setLevel(logging.INFO)
infoHandler.setFormatter(Formatter(LOG_FORMAT))
infoLogger.addHandler(infoHandler)
infoLogger.addHandler(logging.StreamHandler())

It works fine for me, i.e. debugLogger.debug('foo') goes to the debug logfile. How are you trying to use the loggers? — Jussi Nurminen
– Jussi Nurminen, Commented Mar 2, 2020 at 20:08
Thanks, I guess what I am doing wrong is that I am just using logging.info() or logging.error(). Is there a way to keep it this way in my code but still have the debuggers as above? So not debugLogger.error(), but logging.error()? — GeekGeek4
– GeekGeek4, Commented Mar 2, 2020 at 20:13

Jussi Nurminen · Accepted Answer · 2020-03-02 20:42:13Z

The logging.* functions that you are calling log to the root logger. That's why you don't see any output; you haven't configured any handlers for the root logger. You have only configured handlers for your own loggers, which you are not using.

If you want to use the logging.* functions, you need to first configure the root logger, which you can get by calling getLogger without any arguments. So the code might look like:

import logging
import logging.handlers


root_logger = logging.getLogger()

info_handler = logging.handlers.RotatingFileHandler(filename='infolog.txt')
info_handler.setLevel(logging.INFO)

stream_handler = logging.StreamHandler()
stream_handler.setLevel(logging.INFO)

debug_handler = logging.handlers.RotatingFileHandler(filename='debuglog.txt')
debug_handler.setLevel(logging.DEBUG)

root_logger.addHandler(stream_handler)
root_logger.addHandler(debug_handler)
root_logger.addHandler(info_handler)

# this is needed, since the severity is WARNING by default,
# i.e. it would not log any debug messages
root_logger.setLevel(logging.DEBUG)

root_logger.debug('this is a debug message')
root_logger.info('this is an info message')

Collectives™ on Stack Overflow

Python multiple loggers not working. How to configure multiple loggers with different levels?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related