Friday, September 03, 2010

A Standard Way to Use Python's Logging Module

The documentation for Python's logging module shows you its great features, but it doesn't mention standard usage if you are writing a little application or a library.

Make a separate logger for each file, and name the loggers to match the hierarchy of modules. For the file acert/hfesr/, it starts with:

import logging
logger = logging.getLogger('acert.hfesr.Runner')
class Runner(object):
def __init__(self):
logger.debug('Initializing Runner')

That's quite simple. Then you can enable and disable logging by file or by module.

The second tip is that, if you have written a library, don't use logging.basicConfig() in that library because it makes logging handlers that are difficult for subsequent client applications to quiet.


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