Python : change numeric values of logging levels

Question

The default Numeric values of logging levels is :

I need to change this values and set the DEBUG value to 20 and INFO to 10

Please let me know how to do it.

At present this is my code :

log =logging.getLogger(__name__)

log.setLevel(logging.DEBUG)
formatter =logging.Formatter('[%(module)s](%(lineno)d) [%(levelname)s] : %(message)s')

file_handler = logging.FileHandler('debug.log', mode='w')
file_handler.setFormatter(formatter)
log.addHandler(file_handler)


stream_handler = logging.StreamHandler()
stream_handler.setFormatter(formatter)
log.addHandler(stream_handler)


log.warning('This is a warning')
log.error('This is an error')
log.info('This is an INFO')
log.debug('This is an DEBUG')
log.critical('This is an CRITICAL')

I need to put only debug messages in a file not other messages. In the present scenario, in case I want to do it, I will have to set the level to "DEBUG" for file handler. If I do that INFO messages also go in the debug.log — Ashish, Aug 16 '20 at 05:51
Okay so what you are really asking is how to set up a handler which is **only** for DEBUG messages, rather than everything DEBUG and higher. I'm afraid I don't know the answer, but it is not self-evident that trying to tamper with the symbolic constants will be the way to implement this, so I suggest that you edit the question to reflect what you are actually trying to achieve (and have just said in the comments), and leave it to people to suggest the most appropriate implementation. — alani, Aug 16 '20 at 05:57

score 1 · Answer 1 · answered Aug 16 '20 at 06:11

1

You can use a filter on the handler instead which can select messages with a specific level.

See logging with filters

The body of the filter method on the Filter subclass in this case would be:

return record.getLevel() == logging.DEBUG

answered Aug 16 '20 at 06:11

Dan D.

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score 0 · Accepted Answer · answered Aug 16 '20 at 07:15

This is how I solved

I created a filter like this :

class debugFilter(logging.Filter):
    def filter(self, record):
        if (record.levelno == 10):
            return True
        else:
            return False

and main code :

file_handler = logging.FileHandler('debug.log', mode='w')
file_handler.addFilter(debugFilter())
file_handler.setFormatter(formatter)
log.addHandler(file_handler)

Python : change numeric values of logging levels

2 Answers2