Logging Demo

com.py

from log import setup_logger


class Communicator(object):

    def __init__(self, logger=None):
        if logger is None:
            logger = setup_logger(__name__)

        self.log = logger

    def send(self, data):
        self.log.info('Sending %s bytes of data' % len(data))

log.py

"""
Helper module to factor out setting up the logger and attaching a FileHandler.
"""

from logging import FileHandler
import logging


def setup_logger(name):
    logger = logging.getLogger(name)
    handler = FileHandler('%s.log' % name)
    logger.addHandler(handler)
    return logger

main.py

from svc_anonymous import func
from svc_bar import bar
from svc_foo import foo
import logging


# Add a StreamHandler for the root logger, so we get some console output in
# addition to file logging (for easy of testing). Also set the level for
# the root level to INFO so our messages don't get filtered.
logging.basicConfig(level=logging.INFO)


foo()
bar()
func()

svc_anonymous.py

from com import Communicator


def func():
    # No logger being passed in
    c = Communicator()
    c.send('anonymous')

svc_bar.py

from com import Communicator
from log import setup_logger


logger = setup_logger(__name__)


def bar():
    c = Communicator(logger)
    c.send('bar')

svc_foo.py

from com import Communicator
from log import setup_logger


logger = setup_logger(__name__)


def foo():
    c = Communicator(logger)
    c.send('foo')