vmodule

This is a tiny project with no deps to add extra levels to stdlib logging, and also something you can run from your main that processes logger-specific verbosity.

This is inspired by glog, which considers VLOG(1) to be a more restrictive version of LOG(INFO). For simplicity we just map that onto numeric severities.

Here's a combined demo of how you might use this library -- we don't depend on click but you certainly can:

from logging import getLogger
from typing import Optional

import click

from vmodule import VLOG_1, VLOG_2, vmodule_init

LOG = getLogger(__name__)


@click.command()
@click.option("-v", type=int)
@click.option("--vmodule")
def main(v: Optional[int], vmodule: Optional[str]) -> None:
    vmodule_init(v, vmodule)
    LOG.warning("Warn")
    LOG.info("Starting up")
    LOG.log(VLOG_1, "Verbose %d", 1)
    LOG.log(VLOG_2, "Verbose %d", 2)
    LOG.debug("foo")


if __name__ == "__main__":
    main()

If you're writing a library, it's even easier:

from logging import getLogger
from vmodule import VLOG_1

LOG = getLogger(__name__)

def foo(...):
    LOG.info("Starting up")
    LOG.log(VLOG_1, "Verbose %d", 1)

Command line parsing

If you use the example above,

(unset)  -> WARNING
-v 0     -> INFO
-v 1     -> VLOG_1
-v 2     -> VLOG_2
-v 3     -> VLOG_3
-v 10    -> DEBUG (by accident)

You can also specify those same numbers with --vmodule although there are two gotchas:

1. You CLI's logger is quite possibly called "__main__".
2. This doesn't take wildcards or use hierarchy. You need to specify actual logger names.

--vmodule filelock=10,concurrent.futures=0

sets filelock to DEBUG
sets concurrent.futures to INFO

Version Compat

Usage of this library should work back to 3.7, but development (and mypy compatibility) only on 3.10-3.12. Linting requires 3.12 for full fidelity.

License

vmodule is copyright Tim Hatch, and licensed under the MIT license. I am providing code in this repository to you under an open source license. This is my personal repository; the license you receive to my code is from me and not from my employer. See the LICENSE file for details.