Include traceback to JSON

[sky-py]

Is there any way to add loguru's beautiful traceback (like that when adding backtrace=True, diagnose=True to log) to CUSTOM JSON log?

For example for

from loguru import logger
import json


def json_formatter(record):
    log_object = {
        'timestamp': record['time'].strftime('%Y-%m-%d %H:%M:%S'),
        'level': record['level'].name,
        'message': record['message'],
        **record['extra']
    }

    return json.dumps(log_object, ensure_ascii=False)

def patching(record):
    record['extra']['serialized'] = json_formatter(record)

logger = logger.patch(patching)

logger.add('error.log',
           level='ERROR',
           format='{extra[serialized]}',
           )


@logger.catch
def error():
    x = 10
    y = 0
    z = x / y

error()

getting:

{"timestamp": "2024-10-06 21:15:27", "level": "ERROR", "message": "An error has been caught in function '<module>', process 'MainProcess' (5572), thread 'MainThread' (7948):"}
Traceback (most recent call last):

> File "D:\User\Dropbox\Python\test\test3.py", line 34, in <module>
    error()
    └ <function error at 0x000001FF66294EA0>

  File "D:\User\Dropbox\Python\test\test3.py", line 32, in error
    z = x / y
        │   └ 0
        └ 10

ZeroDivisionError: division by zero

How to include

Traceback (most recent call last):

> File "D:\User\Dropbox\Python\test\test3.py", line 34, in <module>
    error()
    └ <function error at 0x000001FF66294EA0>

  File "D:\User\Dropbox\Python\test\test3.py", line 32, in error
    z = x / y
        │   └ 0
        └ 10

ZeroDivisionError: division by zero

to JSON?

[Delgan]

There is no built-in way, but you can use the better_exception library from which the Loguru tracebacks are derived.

[dmyersturnbull]

I find serialization unhelpful without tracebacks, so I took a similar approach to @sky-py. I checked out better_exception (thanks @Delgan) and ended up serializing the tracebacks (as list[dict[...]]).

While this works, the need for patch makes it awkward. It means I need a global logger = loguru_logger.patch(...) and to from myapp.core import logger. It's a little bit of unnecessary coupling.

It's not a big deal, just something I felt worth pointing out. I did add a way to limit the traceback depth (for serialized and non-serialized), per logging statement, which is actually pretty helpful.

[Delgan]

@dmyersturnbull Can you use the patcher attribute of the logger.configure() method maybe?
That would patch the logger globally, avoiding the need for a custom from myapp.core import logger import.