Disable logging unless code is running in CLI

[benthorner]

Fixes regression from ¹.

Previously this repo used Python's inbuilt logger, which does
not emit INFO or DEBUG logs by default. loguru emits all logs
by default. This fixes that by disabling loguru unless the code
is running in CLI mode, which is when logs are actually used.

Footnotes

1. https://github.com/avaldebe/PyPMS/commit/ecd0c9d1cd0e88284299fecc6416f5f01cadf10d ↩

[avaldebe]

I'm not sure that this is the right approach for library usage.
In principle is it up to the library user to decide on the logger level.

[avaldebe]

why change the name of the CLI entry point?

[benthorner]

typer looks for an entry point called main, but I want to make this a function so I can override the logging behaviour before the main CLI starts. We can't have:

main = Typer(...)

...

def main(): ...

[avaldebe]

Not sure that disabling the longing is the right behaviour for library use.
In principle, the library user should decide the logging level.

[benthorner]

I have two problems with this:

1. The default logging level is "DEBUG", which is not a sensible default.

import loguru
loguru.logger.debug('test')
2023-01-07 10:27:45.491 | DEBUG    | __main__:<module>:1 - test

2. PyPMS logs now have to be configured using a different framework.

import logging
logging.configure({ ... })  # main logging for other libraries

import loguru
loguru.logger.configure(...)  # special config just for PyPMS

Normally I don't need DEBUG logs for PyPMS. If I do need them, then as a developer I am willing to go find out how to turn them on. Conversely, when I start using a library I don't want to spend extra effort working out how to switch all the DEBUG logs off to stop them polluting my normal / day-to-day logs.

logger.disable("pms") seemed like the easiest solution to get back to a sensible default for library users. I also think some documentation would be helpful, but that should be a secondary priority to just having some sensible defaults in the first place - the priority should be ease of use / minimal setup effort.

[avaldebe]

Please do not import private modules. Use pytest.LogCaptureFixture instread.

[benthorner]

I get an error if I do this:

E   ModuleNotFoundError: No module named 'pytest.logging'

I'm just following loguru's own docs here: https://loguru.readthedocs.io/en/stable/resources/migration.html#making-things-work-with-pytest-and-caplog

[avaldebe]

can this not be done on the CLI callback function?

[benthorner]

Good question. I did try this originally but it doesn't work for testing: some of the other tests execute the callback, which overrides the package default (that logging is disabled).

Since the purpose of the test I added is to check for regression in the package default, I needed to put this line somewhere where no other test would cause it to run.

I admit it's not a great change or a great test, but since this is the second PR to try and make logging work better for library users, I wanted to put something in to protect the behaviour.

[benthorner]

@avaldebe library users can still customise logging with the changes here - they just need to enable the logger first. The the new default logging level of "DEBUG" (for library users) is a regression from ecd0c9d.

How can we get back to that without requiring library users to learn about loguru?

[avaldebe]

I get your point. I'll merge your PR and publish a new version now, and will try to find a better solution later.

[benthorner]

Thanks @avaldebe - logs are now clean again 🎉. Appreciate it!