child_loggers.py

#
# Example of a child loggers
#

import logging
from logging.config import dictConfig


LOGGING_CFG = {
    "version": 1,
    "disable_existing_loggers": "False",
    "formatters": {
        "console": {
            'format': '[%(levelname)s] %(name)s: %(message)s',
        },
    },
    "handlers": {
        "console": {
            "class": "logging.StreamHandler",  
            "formatter": "console",
        },
    },
    "loggers": {
        "crmsh": {
            "handlers": [
                         "console",
                         ],
            "level": "DEBUG",
        },
        "crmsh.sbd": {
            # Comment/uncomment to see the effect:
            "level": "WARNING",
        },
        "crmsh.bootstrap": {
            # Comment/uncomment to see the effect:
            "level": "ERROR",
        },
        
    }
}

dictConfig(LOGGING_CFG)


def main():
    # This is our parent logger:
    crmsh_log = logging.getLogger("crmsh")

    # These are our child loggers with different log levels:
    crmsh_sbd_log = logging.getLogger("crmsh.sbd")
    crmsh_bs_log = logging.getLogger("crmsh.bootstrap")

    crmsh_log.debug("A debug message")
    crmsh_log.info("An info message")
    crmsh_log.warning("A warning message")
    crmsh_log.error("An error message")

    # If you configured the dictionary accordingly,
    # you don't need to set the logger level manually.
    # In case you want, use this:
    # crmsh_sbd_log.setLevel(logging.WARNING)
    crmsh_sbd_log.debug("Another debug message in a child logger")
    crmsh_sbd_log.warning("A warning message in a child logger")
    crmsh_sbd_log.error("An error message in a child logger")

    # Only some are shown, because of the configuration:
    crmsh_bs_log.debug("An debug message from a logger with ERROR level")
    crmsh_bs_log.warning("An warning message from a logger with ERROR level")
    crmsh_bs_log.error("An error message from a logger with ERROR level")
    crmsh_bs_log.fatal("An fatal message from a logger with ERROR level")


if __name__ == "__main__":
    main()