How to customize Python’s logging level without ‘configuration madness’

Python’s standard logging library offers a standard module (logging.config) for configuration, and it offers a lot of options. Most of them look like a pain. If you just want to configure the logging level, for example, you might wonder: Do I have to write an entire file listing handlers and files and other configuration options just to say I only want to see INFO-level messages and above?

Fortunately, there’s a much easier way to configure your code’s logging level. You can simply call logging.basicConfig() with the configuration settings you want to change. In this case, you’ll want something like:

import logging
import os

...

def main():
    ...
    logging.basicConfig(
        level=getattr(logging, os.getenv("LOGGING_LEVEL", "INFO"))
    )

This call to basicConfig() will set the logging level to the one defined by the environment variable LOGGING_LEVEL (which could be, for example, ERROR, WARNING, INFO, or DEBUG by default). If the user doesn’t set LOGGING_LEVEL, it defaults to the INFO level.

Of course, we don’t have to get the logging level config from an environment variable—it could come from anywhere. If this is a CLI app, you could define a --logging-level argument that controls the logging level. You could define and load your own simple configuration file (perhaps a json file) that includes a logging level value. The sky’s the limit.

So, don’t worry about setting up a complicated logging config file. You can easily configure logging with a simple call to basicConfig().