remove logging.basicConfig()

[alvinchow86]

this library shouldn't be calling logging.basicConfig(), since it's a global configuration and will muck with existing logging setups. I think this call is meant for the top-level application to control

[yschatzberg]

@alvinchow86 Thanks for submitting this, before I can merge it we'd need to figure out how to maintain backwards compatibility. Did you have any suggestions on this?

[TallGirlVanessa]

Huh, ran into this yesterday. We started using sift and were surprised to find that our logging configuration got messed up, just by importing a new library, without even calling anything in it. I mean, on one hand I understand the desire to make things "just work". But I'd definitely vote for removing it and calling it out as a breaking change.

If sift does need to add logging handlers, I think it'd be better to do it the way Werkzeug does it (though it's worth noting that Werkzeug's a framework, not a library, so it's not surprising that it adds logging handlers). From https://github.com/mitsuhiko/werkzeug/blob/master/werkzeug/_internal.py#L75-L87 :

def _log(type, message, *args, **kwargs):
    """Log into the internal werkzeug logger."""
    global _logger
    if _logger is None:
        import logging
        _logger = logging.getLogger('werkzeug')
        # Only set up a default log handler if the
        # end-user application didn't set anything up.
        if not logging.root.handlers and _logger.level == logging.NOTSET:
            _logger.setLevel(logging.INFO)
            handler = logging.StreamHandler()
            _logger.addHandler(handler)
    getattr(_logger, type)(message.rstrip(), *args, **kwargs)

Then it's called like this:

_log('info', ' * Restarting with reloader')

Advantages:

• It only adds a handler to the module's logger, not the root logger
• It only adds the handler when the module's called, rather than when the module's imported, so that importing a module doesn't have surprising side effects

(That global statement's kind of annoying though. I'd refactor this into an object.)

[sww]

How about

API_URL = 'https://api.siftscience.com'
sift_logger = logging.getLogger('sift_client')
if not logging.root.handlers and sift_logger.level == logging.NOTSET:
    sift_logger.setLevel(logging.INFO)
    handler = logging.StreamHandler()
    sift_logger.addHandler(handler)

?

It's a more focused approach and would not affect the global logging setup.

[philfreo]

We also installed sift and were unhappy to find out that using the client messes up all our existing logging. @yschatzberg Any chance for a fix here soon to not call basicConfig in all cases?

[TallGirlVanessa]

@sww That's better, but I'd still argue installing handlers on import is unexpected behavior, especially for a library. Werkzeug's check for a root handler only works because it runs after client code has been initialized.

[sripadsriram]

cc @fredsadaghiani

[fredsadaghiani]

Thanks, a better solution might be to just use warnings.warn(... rather than install a logger. Thoughts?

[JohnMcSpedon]

@fredsadaghiani's fix was implemented in https://github.com/SiftScience/sift-python/pull/31 I've pushed a new version of this library to PyPI. pip install --upgrade sift will now install sift-python 1.1.2.2, which should no longer affect existing logging config

[philfreo]

Thank you!

[TallGirlVanessa]

Great, thanks a bunch!

[fredsadaghiani]

Closing. See #31 instead.