Does Loguru have built-in support for running code before/after logging a message?

Does Loguru have built-in support for running code before/after logging a message? What I’m trying to do is get loguru.logger.warning to also emit warnings.warn when called.

The use case is that I have a lot of calls to loguru.logger.warning throughout the project. I’ve now been asked to update things so that the exit code is non-zero if a warning is emitted. For example:

def cli():
    exit_code = 0  # success
    with warnings.capture_warnings(record=True) as w:
        try:
            main.run()
        except Exception:
            exit_code = 1  # error

        if len(w) > 0:
            exit_code = 3  # success-with-warnings
    sys.exit(exit_code)

What I could do is go find all instances of logger.warning(msg) and add a line warnings.warn(msg) afterwards, but it seems like there’s gotta be a better way.

If there’s nothing built-in, I’ll end up doing something like:

# -*- coding: utf-8 -*-
# __init__.py
import warnings

# Normally I'd just have from `loguru import logger` here
from loguru._logger import Logger as _Logger
from loguru._logger import Core as _Core

# Monkeypatch the loguru logger so that logger.warning also emits warning.warn
class CustomLogger(_Logger):
    def warning(__self, __message, *args, **kwargs):
        r"""Log ``message.format(*args, **kwargs)`` with severity ``'WARNING'``."""
        __self._log("WARNING", None, False, __self._options, __message, args, kwargs)
        warnings.warn(__message)

# basically the same as loguru/__init__.py
logger = CustomLogger(
    core=_Core(),
    exception=None,
    depth=0,
    record=False,
    lazy=False,
    colors=False,
    raw=False,
    capture=True,
    patcher=None,
    extra={},
)

[Delgan]

I’m closing this issue now that I added the warnings.warn() example to the documentation. 👍

[Delgan]

Yeah, I think sinks make a good solution for this purpose. Unless there are use cases for which they are not enough, I prefer not to add a new method to the logger. Maybe it’s a bit indirect and tricky, but I think I’ll just add this snippet in the documentation. 👍