How to turn off logging statements without removing them from the code

Question

If there are logging statements spread throughout a codebase, how do I set up the logger so I don't have to comment out each call to the logger when deploying the code into production?

Here's my current code:

import logging


logging.basicConfig(filename='./example.log', level=logging.DEBUG, 
                    format='%(asctime)s %(name)-12s %(levelname)-8s %(message)s',
                    datefmt='%m-%d %H:%M')

logging.debug('debug failed')
logging.info('info failed')
logging.warning('A warning')

Answer 1

Instead of using the basicConfig, you can set up the logger more explicitly with the handlers you want, based on any criteria.

import logging

log = logging.getLogger("FOO")
log.setLevel(logging.DEBUG)

# needs a handler
log.info('info')
#No handlers could be found for logger "FOO"

ch = logging.StreamHandler()
log.addHandler(ch)
log.info('info')
# info

log.removeHandler(ch)

noop = logging.NullHandler()
log.addHandler(noop)
# nothing happens here
log.info('info')

You can have a conditional statement that either adds the handler you want if you are running in debug mode, or you can add a NullHandler that just absorbs the log messages. You can also configure the levels individually of each handler, so that you would always see warnings and above. Each handler can have its own level, in addition to the main logger.

You can refer to the tutorials on how to get more specific with levels, handlers, and formatting.