stdlogkit 0.2.0

A small stdlib logging auto-configuration kit with colored multiline logs and log-once helpers.

stdlogkit

stdlogkit is a vLLM-style, vLLM-independent wrapper around Python's standard logging package.

Importing it configures logging immediately. Like vLLM, the default configuration installs a handler on a named root logger, stdlogkit, and child loggers propagate to it.

import stdlogkit

logger = stdlogkit.init_logger("stdlogkit.app")
logger.info("hello")
logger.warning_once("this warning appears once")

Default output:

INFO 06-24 12:00:01 [example.py:5] hello
WARNING 06-24 12:00:01 [example.py:6] this warning appears once

The default format intentionally does not include process name or PID, matching vLLM. Single-process and multiprocessing logs therefore use the same fields.

vLLM Compatibility

This package mirrors vLLM's logging behavior while remaining fully decoupled:

• Uses logging.config.dictConfig.
• Configures one named logger by default, stdlogkit, with propagate=false.
• Child loggers such as stdlogkit.app have no handler and propagate upward.
• init_logger(name) patches debug_once, info_once, and warning_once onto that returned logger instance.
• *_once uses functools.lru_cache, so arguments must be hashable, as in vLLM.
• Multiline logs are aligned with the same prefix strategy as vLLM.
• Color constants match vLLM exactly.

Colors

The ANSI color values are identical to vLLM:

Level/field	ANSI code
DEBUG	\033[37m
INFO	\033[32m
WARNING	\033[33m
ERROR	\033[31m
CRITICAL	\033[35m
timestamp and file info	\033[90m
reset	\033[0m

Environment Variables

Variable	Default	Description
STDLOGKIT_CONFIGURE_LOGGING	1	Set 0 to disable auto configuration.
STDLOGKIT_LOGGING_LEVEL	INFO	Named logger and handler level.
STDLOGKIT_LOGGING_STREAM	ext://sys.stdout	Handler stream.
STDLOGKIT_LOGGING_PREFIX	empty	Prefix prepended to every log line.
STDLOGKIT_LOGGING_COLOR	auto	auto, 1, or 0.
STDLOGKIT_LOGGING_CONFIG_PATH	unset	Path to a JSON dictConfig file.
STDLOGKIT_LOGGER_NAME	stdlogkit	Named logger to configure.
NO_COLOR	0	Standard flag to disable ANSI colors.

Custom JSON Config

{
  "version": 1,
  "disable_existing_loggers": false,
  "formatters": {
    "plain": {
      "class": "stdlogkit.formatter.NewLineFormatter",
      "format": "%(levelname)s %(asctime)s [%(fileinfo)s:%(lineno)d] %(message)s",
      "datefmt": "%m-%d %H:%M:%S"
    }
  },
  "handlers": {
    "console": {
      "class": "logging.StreamHandler",
      "formatter": "plain",
      "level": "INFO",
      "stream": "ext://sys.stdout"
    }
  },
  "loggers": {
    "stdlogkit": {
      "handlers": ["console"],
      "level": "INFO",
      "propagate": false
    }
  }
}

Run with:

STDLOGKIT_LOGGING_CONFIG_PATH=/path/to/logging.json python app.py

Development

cd standalone_logging_pkg
uv venv --python 3.12
uv pip install -e ".[dev]"
PYTHONPATH=src .venv/bin/python -m unittest discover -s tests -v
uv build

Publish to PyPI

Before publishing, make sure the project name in pyproject.toml is available on PyPI and replace the placeholder author/repository metadata.

cd standalone_logging_pkg
uv build
uv publish --token "$PYPI_TOKEN"

For TestPyPI:

uv publish --publish-url https://test.pypi.org/legacy/ --token "$TEST_PYPI_TOKEN"