custom logging handler

#!/usr/bin/env python3
import sys
import logging
import logging.handlers
from basename import get_basename

logger = logging.getLogger("tst")

class DaveHandler(logging.StreamHandler):
    def emit(self, record):
        msg = self.format(record)
        print("dave sez {}".format(msg), file=sys.stderr)

def main():
    level = logging.DEBUG

    # also log to file because lots of stuff to keep track
    logfilename = get_basename(__file__)+".log"
    # formatter that writes iso8601 timestamps
    formatter = logging.Formatter("%(asctime)s:%(levelname)s:%(name)s:%(message)s", "%Y%m%dT%H%M%SZ")
    handler = logging.handlers.WatchedFileHandler(logfilename)
    handler.setLevel(level)
    handler.setFormatter(formatter)
    logger.addHandler(handler)

    # davep 20170607 ; tinkering with custom handler
    handler = DaveHandler()
    handler.setLevel(level)
    # use same formatter
    handler.setFormatter(formatter)
    # add to the global logger
    logger.addHandler(handler)
    logger.setLevel(level=level)

    logger.debug("debug message")
    logger.info("info message")
    logger.warning("warning message")
    logger.error("error message")

if __name__ == '__main__':
    main()