Python logging coloredlogs styling utility functions

logio.py

import sys
import os
from loguru import logger
from tqdm.auto import tqdm
from functools import partialmethod


class TqdmStream(object):

    @classmethod
    def write(_, msg):
        tqdm.write(msg, file=sys.stderr, end="")

    @classmethod
    def flush(_):
        sys.stderr.flush()


def logging_func():
    logger.debug("debug")
    logger.info("info")
    logger.notice("notice")
    logger.warning("warning")
    logger.error("error")


def init_logger(
    logger,
    level,
    fmt: str = None,
    logdir: str = None,
    filename: str = None,
    rotation_minutes: int = 1,
    retention_days: int = 14,
    serialize: bool = False,
):

    default_fmt = (
        "<dim>{time:YYYY-MM-DD HH:mm:ss}</dim> <level>{level:<8}</level> | "
        "<blue>{name:^15}:{function:^15}:{line:>3}</blue> - {message}"
    )
    _fmt = fmt or default_fmt

    # if not TqdmStream, we should use: 'sys.stderr'
    handlers = [
        {"sink": TqdmStream(), "format": _fmt, "colorize": True, "level": level},
    ]
    # logging to file
    if logdir and filename:
        handlers.append(
            {
                "sink": os.path.join(logdir, filename),
                "rotation": f"{rotation_minutes} minute",
                "retention": f"{retention_days} days",
                "serialize": serialize,
            }
        )

    config = {"handlers": handlers}
    logger.configure(**config)

    # Add a 'NOTICE' level
    logger.level("NOTICE", no=25, icon="🤖", color="<cyan><bold>")
    logger.__class__.notice = partialmethod(logger.__class__.log, "NOTICE")


if __name__ == "__main__":
    import time

    init_logger(logger, "DEBUG")

    levels = ["DEBUG", "INFO", "NOTICE", "WARNING", "ERROR"]
    for i in tqdm(range(10)):
        logger.log(levels[i % 5], f"Ahhhhh... {i}")
        time.sleep(0.2)

python_colored_logging.py

def install_logger(
    logger, level, fmt="%(levelname)-8s %(name)-25s:%(lineno)4d - %(message)-50s"
):
    """ Configures the given logger; format, logging level, style, etc """
    import coloredlogs

    # More style info at:
    # https://coloredlogs.readthedocs.io/en/latest/api.html
    field_styles = coloredlogs.DEFAULT_FIELD_STYLES.copy()
    field_styles["asctime"] = {}
    level_styles = coloredlogs.DEFAULT_LEVEL_STYLES.copy()
    level_styles["debug"] = {"color": "white", "faint": True}
    level_styles["notice"] = {"color": "cyan", "bold": True}

    coloredlogs.install(
        logger=logger,
        level=level,
        use_chroot=False,
        fmt=fmt,
        level_styles=level_styles,
        field_styles=field_styles,
    )
    
    
def add_new_level():
    """ Creates a new 'notice' logging level """
    # inspired by: 
    # https://stackoverflow.com/questions/2183233/how-to-add-a-custom-loglevel-to-pythons-logging-facility 
    NOTICE_LEVEL_NUM = 25
    logging.addLevelName(NOTICE_LEVEL_NUM, "NOTICE")

    def notice(self, message, *args, **kws):
        if self.isEnabledFor(NOTICE_LEVEL_NUM):
            self._log(NOTICE_LEVEL_NUM, message, args, **kws)

    logging.Logger.notice = notice

• logio.py uses loguru
• python_colored_logging.py uses the standard logging and coloredlogs

The logio options seems easier to manage and configure with rotating logfiles

When using loguru with uvicorn you might want to override uvicorn's default logger, this gist shows how