configuring a logging.Logger for nox

Adding a logger to your noxfile.py is very helpful when debugging, and also to see what's going on in a pipeline (for example).

Example config dict

logging_config: dict = {
        "version": 1,
        "disable_existing_loggers": False,
        "loggers": {
            "nox": {
                "level": level_name.upper(),
                "handlers": ["console"],
                "propagate": False,
            }
        },
        "handlers": {
            "console": {
                "class": "logging.StreamHandler",
                "formatter": "nox",
                "level": "DEBUG",
                "stream": "ext://sys.stdout",
            }
        },
        "formatters": {
            "nox": {
                "format": "[NOX] [%(asctime)s] [%(levelname)s] [%(name)s]: %(message)s",
                "datefmt": "%Y-%m-%D %H:%M:%S",
            }
        },
    }

Example configure a nox logger

import logging
import logging.config
import logging.handlers

import nox

## Detect container env, or default to False
if "CONTAINER_ENV" in os.environ:
    CONTAINER_ENV: bool = os.environ["CONTAINER_ENV"]
else:
    CONTAINER_ENV: bool = False


def setup_nox_logging(
    level_name: str = "DEBUG", disable_loggers: list[str] | None = []
) -> None:
    """Configure a logger for the Nox module.

    Params:
        level_name (str): The uppercase string repesenting a logging logLevel.
        disable_loggers (list[str] | None): A list of logger names to disable, i.e. for 3rd party apps.
            Note: Disabling means setting the logLevel to `WARNING`, so you can still see errors.

    """
    ## If container environment detected, default to logging.DEBUG
    if CONTAINER_ENV:
        level_name: str = "DEBUG"

    logging_config: dict = {
        "version": 1,
        "disable_existing_loggers": False,
        "loggers": {
            "nox": {
                "level": level_name.upper(),
                "handlers": ["console"],
                "propagate": False,
            }
        },
        "handlers": {
            "console": {
                "class": "logging.StreamHandler",
                "formatter": "nox",
                "level": "DEBUG",
                "stream": "ext://sys.stdout",
            }
        },
        "formatters": {
            "nox": {
                "format": "[NOX] [%(asctime)s] [%(levelname)s] [%(name)s]: %(message)s",
                "datefmt": "%Y-%m-%D %H:%M:%S",
            }
        },
    }

    ## Configure logging. Only run this once in an application
    logging.config.dictConfig(config=logging_config)

    ## Disable loggers by name. Sets logLevel to logging.WARNING to suppress all but warnings & errors
    for _logger in disable_loggers:
        logging.getLogger(_logger).setLevel(logging.WARNING)


## Configure logging
setup_nox_logging()

## Create logger for this module
log: logging.Logger = logging.getLogger("nox")

Disable loggers by name

If you use the setup_nox_logging() method with a list of logger names (as str objects, i.e. urllib3, sqlalchemy, etc), those loggers will have their log level set to logging.WARNING. This effectively silences them; warning, error, and critical messages will still show.

def setup_nox_logging(
    level_name: str = "DEBUG", disable_loggers: list[str] | None = []
) -> None:

    ...

    ## Disable loggers by name. Sets logLevel to logging.WARNING to suppress all but warnings & errors
    for _logger in disable_loggers:
        logging.getLogger(_logger).setLevel(logging.WARNING)


## Disable the requests and urllib3 loggers
setup_nox_logging(disable_loggers=["requests", "urllib3"])