Python logging configuration example with multiple modules.

main.py

import logging
from logging.config import dictConfig

# adding custom level
logging.VERBOSE = 5
logging._levelNames.update({
    5: 'VERBOSE', 
    'VERBOSE': 5,
})

# method for custom level
def verbose(self, msg, *args, **kwargs):
    if self.isEnabledFor(logging.VERBOSE):
        self._log(logging.VERBOSE, msg, args, **kwargs)

logging.Logger.verbose = verbose


dictConfig({
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': {
        'standard': {
            'format': '%(asctime)s - [%(levelname)s] %(name)s [%(module)s.%(funcName)s:%(lineno)d]: %(message)s', 
            'datefmt': '%Y-%m-%d %H:%M:%S',
        }
    },
   'handlers' : {
        'default': {
            'level': 'VERBOSE', 
            'class': 'logging.StreamHandler',
            'formatter': 'standard',
        }
   }, 
   'loggers': {
        '__main__': { # logging from this module will be logged in VERBOSE level
            'handlers' : ['default'], 
            'level': 'VERBOSE', 
            'propagate': False,
        },
   },
   'root': {
        'level': 'INFO',
        'handlers': ['default']
   },
})

# module logs message, so importing it only after logging has been configured
from other import foo

logger = logging.getLogger(__name__)

logger.info('Info log message')
logger.debug('debug message')
foo()
logger.error('error example')
logger.verbose('verbose log message')
try:
    raise Exception('exception message')
except:
    logger.exception('error occured')

other.py

import logging

logger = logging.getLogger(__name__)
logger.warn('warning log message')

def foo():
    logger.debug('depending on configuration this may not be printed')
    logger.info('Log message from function foo.')

output

2013-01-15 20:05:51 - [WARNING] other [other.<module>:4]: warning log message
2013-01-15 20:05:51 - [INFO] __main__ [main.<module>:53]: Info log message
2013-01-15 20:05:51 - [DEBUG] __main__ [main.<module>:54]: debug message
2013-01-15 20:05:51 - [INFO] other [other.foo:8]: Log message from function foo.
2013-01-15 20:05:51 - [ERROR] __main__ [main.<module>:56]: error example
2013-01-15 20:05:51 - [VERBOSE] __main__ [main.<module>:57]: verbose log message
2013-01-15 20:05:51 - [ERROR] __main__ [main.<module>:61]: error occured
Traceback (most recent call last):
  File "main.py", line 59, in <module>
    raise Exception('exception message')
Exception: exception message