logger.exception error without the traceback?

[grheard]

More of a question than an issue.

Is there a way to get the error portion of logger.exception without the traceback for a given sink?

I have an application that posts errors to a status bar and a separate sink that logs to a file. The file sink has backtrace=True and the method sink for the status bar has backtrace=False but it still receives the traceback and I would rather it still get the error description minus the traceback.

[Delgan]

Hi.

Loguru respects the sys.tracebacklimit value. You can set it to 0 and effectively disable any traceback.

from loguru import logger
import sys

sys.tracebacklimit = 0

def div(a, b):
    a / b

def main():
    try:
        div(1, 0)
    except:
        logger.exception("Error")

main()

Alternatively, for more fine-grained control, you can simply define and use your own custom exception formatter:

from loguru import logger
import sys

def formatter(record):
    # Simplify the exception.
    if record["exception"] is not None:
        type_, value, tb = record["exception"]
        exc = f"{type_.__name__}: {value}\n"
    else:
        exc = ""

    # Just store the custom value.
    record["extra"]["exc"] = exc

    # Use the custom `exc` instead of the built-in one.
    return "{time} {level} {message}\n{extra[exc]}"


def div(a, b):
    a / b

def main():
    try:
        div(1, 0)
    except:
        logger.exception("Error")

logger.remove()
logger.add(sys.stderr, format=formatter)

main()

[grheard]

Hello Delgan.

Thanks for the response.

I wasn't looking to disable the traceback globally, but rather for a given log sink. In my use case above I have a file logger where I not only want the trace back but I also log loguru's full backtrace analysis. At the same time, I have a status bar where I log warnings errors and exceptions. What I was wondering was if there was an easy loguru way to log only the exception message to a given sink. Since there isn't, I have my sink callback recognize the exception in the message and just extract the message portion of it for that status bar.

Again, thanks for the response.

EDIT:
Sometimes I'm bad at reading. Your alternative formatter is basically what I did for that status bar. In my question I only wondered if there might have been a built-in rather than write my own.

Thanks again. Loguru is fantastic.

[Delgan]

Sometimes I'm bad at reading. Your alternative formatter is basically what I did for that status bar. In my question I only wondered if there might have been a built-in rather than write my own.

No problem. So, to answer your question, there isn't a built-in option at this time. Using custom format is the idiomatic solution. But I've considered potentially introducing an attribute to use a custom exception formatter in the future.

Loguru is fantastic.

Thanks!