Python Logging - Disable logging from imported modules

The problem is that calling getLogger without arguments returns the root logger so when you set the level to logging.DEBUG you are also setting the level for other modules that use that logger.

You can solve this by simply not using the root logger. To do this just pass a name as argument, for example the name of your module:

logger = logging.getLogger('my_module_name')
# as before

this will create a new logger and thus it wont inadvertently change logging level for other modules.

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Obviously you have to use logger.debug instead of logging.debug since the latter is a convenience function that calls the debug method of the root logger.

This is mentioned in the Advanced Logging Tutorial. It also allows you to know which module triggered the log message in a simple way.

Not sure if this is appropriate to post, but I was stuck for a long time & wanted to help out anyone with the same issue, as I hadn't found it anywhere else!

I was getting debug logs from matplotlib despite following the pretty straightforward documentation at the logging advanced tutorial and the troubleshooting. I was initiating my logger in main() of one file and importing a function to create a plot from another file (where I had imported matplotlib).

What worked for me was setting the level of matplotlib before importing it, rather than after as I had for other modules in my main file. This seemed counterintuitive to me so if anyone has insight into how you can set the config for a logger that hasn't been imported yet I'd be curious to find out how this works. Thanks!

In my main file:

import logging
import requests
logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)
logging.getLogger('requests').setLevel(logging.DEBUG)

def main():
  ...

In my plot.py file:

import logging
logging.getLogger('matplotlib').setLevel(logging.WARNING)
import matplotlib.pyplot as plt

def generatePlot():
  ...

If you're going to use the python logging package, it's a common convention to define a logger in every module that uses it.

logger = logging.getLogger(__name__)

Many popular python packages do this, including requests. If a package uses this convention, it's easy to enable/disable logging for it, because the logger name will be the same name as the package (or will be a child of that logger). You can even log it to the same file as your other loggers.

logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)

requests_logger = logging.getLogger('requests')
requests_logger.setLevel(logging.DEBUG)

handler = logging.StreamHandler()
handler.setLevel(logging.DEBUG)
logger.addHandler(handler)
requests_logger.addHandler(handler)