WIP: Expose the default format as DEFAULT_FORMAT

[GitToby]

I tend to have a quick solution to expose my logging with

_ = logger.remove()
_ = logger.add(sys.stderr, format=f"{_defaults.LOGURU_FORMAT} | {{extra}}")

However, accessing private modules is not ideal for code review or API stability. This will expose the format so I can extend it when specifying logging formats.

I'm also thinking this might be nice to have in the formatting step, so that we could define a message as

_ = logger.remove()
_ = logger.add(sys.stderr, format="{defalt_format} | {extra}")

Thoughts welcome - could just be a me thing.

[Delgan]

Hi.

Thanks for the suggestion but the default format isn't meant to be exposed publicly. Instead, I suggest copy-pasting it from source and simply updating it according to your preferences. If this proves too repetitive in the long run, you can also define the environment variable LOGURU_FORMAT once and for all.

Otherwise, you can hack your way around using the built-in inspect module:

default_format = inspect.signature(logger.add).parameters["format"].default

Note that I eventually plan to make {extra} field part of the default format

[GitToby]

gotcha - it really is just to expose the extras in the default format.

its a super neat struct logging approach, which we have to expose every time I init a program.

Is there an issue or something for the {extra} field to be part of the default format? I'd be happy to give it a crack and open a PR.

[Delgan]

The following ticket could be considered related: #1200.

But for now, there are only preliminary discussions, no precise specifications. It's actually more complicated than it looks like, because it's tied to the API change I'm planning for *args / **kwargs and the separation with bind() / contextualize(). All this to pivote toward better structured logging support. To be fair, there is still some side work to be done before a PR could be envisaged.