How To Log Uncaught Exceptions In Python?

Better Stack Team
Updated on February 3, 2023

For this, you can use the sys.excepthook that allows us to attach a handler for any unhandled exception:

#Creating a logger
logger = logging.getLogger(__name__)
logging.basicConfig(filename='example.log', filemode='w', level=logging.DEBUG)

#Creating a handler
def handle_unhandled_exception(exc_type, exc_value, exc_traceback):
    if issubclass(exc_type, KeyboardInterrupt):
                #Will call default excepthook
        sys.__excepthook__(exc_type, exc_value, exc_traceback)
        #Create a critical level log message with info from the except hook.
    logger.critical("Unhandled exception", exc_info=(exc_type, exc_value, exc_traceback))
#Assign the excepthook to the handler
sys.excepthook = handle_unhandled_exception

First, you will create a logger that will take care of your exceptions.

Then create a handler handle_unhandled_exception that you will later attach to the hook. Then call the __excepthook__ provided by the sys module. This method is invoked every time the exception is uncaught.

Use the info from the hook to create a log message and assign this handler to the sys.excepthook.

You can learn more info about sys.excepthook in the offical documentation. .

If you are new to logging in Python, please feel free read our Introduction to Python logging and learn more.

🔭 Want to centralize and monitor your python logs?

Go to Logtail and start your log management in 5 minutes.

Better Uptime Dashboard

Make your mark

Join the writer's program

Are you a developer and love writing and sharing your knowledge with the world? Join our guest writing program and get paid for writing amazing technical guides. We'll get them to the right readers that will appreciate them.

Write for us
Writer of the month
Marin Bezhanov
Marin is a software engineer and architect with a broad range of experience working...
Build on top of Better Stack

Write a script, app or project on top of Better Stack and share it with the world. Make a public repository and share it with us at our email.

or submit a pull request and help us build better products for everyone.

See the full list of amazing projects on github