# main.py
import logging
import mymodule

logger = logging.getLogger(__name__)

def setup_logging():
    # only cofnigure logger if script is main module
    # configuring logger in multiple places is bad
    # only top-level module should configure logger
    if not len(logger.handlers):
        logger.setLevel(logging.DEBUG)
        # create console handler with a higher log level
        ch = logging.StreamHandler()
        ch.setLevel(logging.DEBUG)
        formatter = logging.Formatter('%(levelname)s: %(asctime)s %(funcName)s(%(lineno)d) -- %(message)s', datefmt = '%Y-%m-%d %H:%M:%S')
        ch.setFormatter(formatter)
        logger.addHandler(ch)

if __name__ == '__main__':
    setup_logging()
    logger.info('calling mymodule.myfunc()')
    mymodule.myfunc()

# mymodule.py
import logging

logger = logging.getLogger(__name__)

def myfunc():
    msg = 'myfunc is being called'
    logger.info(msg)
    print('done with myfunc')


if __name__ == '__main__':
     # only cofnigure logger if script is main module
    # configuring logger in multiple places is bad
    # only top-level module should configure logger
    if not len(logger.handlers):
        logger.setLevel(logging.DEBUG)
        # create console handler with a higher log level
        ch = logging.StreamHandler()
        ch.setLevel(logging.DEBUG)
        formatter = logging.Formatter('%(levelname)s: %(asctime)s %(funcName)s(%(lineno)d) -- %(message)s', datefmt = '%Y-%m-%d %H:%M:%S')
        ch.setFormatter(formatter)
        logger.addHandler(ch)
    logger.info('myfunc was executed directly')
    myfunc()

$>python main.py
INFO: 2016-07-14 18:13:04 <module>(22) -- calling mymodule.myfunc()
done with myfunc

$>python main.py
INFO: 2016-07-14 18:13:04 <module>(22) -- calling mymodule.myfunc()
INFO: 2016-07-14 18:15:09 myfunc(8) -- myfunc is being called
done with myfunc

16 log = logging.getLogger() # use this form to initialize the root logger
17 #log = logging.getLogger(__name__) # never use this one

import logging
logger = logging.getLogger()
logger.debug("You will not see this message if you use line 17 in main")