Coloring Python logging output

Sometimes, you just want to color the output of the logging package in Python.

Here's a simple custom formatter which shows how this can be done:

import logging
 
class ColorFormatter(logging.Formatter):
    """Logging Formatter to add colors and count warning / errors"""
 
    grey   = "\x1b[90m"
    green  = "\x1b[92m"
    yellow = "\x1b[93m"
    red    = "\x1b[91m"
    reset  = "\x1b[0m"
    format = "%(asctime)s | %(levelname)-5.5s | %(message)s"
 
    FORMATS = {
        logging.DEBUG: grey + format + reset,
        logging.INFO: green + format + reset,
        logging.WARNING: yellow + format + reset,
        logging.ERROR: red + format + reset,
        logging.CRITICAL: red + format + reset
    }
 
    def format(self, record):
        record.levelname = 'WARN' if record.levelname == 'WARNING' else record.levelname
        record.levelname = 'ERROR' if record.levelname == 'CRITICAL' else record.levelname
        log_fmt = self.FORMATS.get(record.levelno)
        formatter = logging.Formatter(log_fmt)
        return formatter.format(record)
 
def configure_logging():
 
    logger = logging.getLogger()
    logger.setLevel(logging.DEBUG)
 
    ch = logging.StreamHandler()
    ch.setLevel(logging.DEBUG)
    ch.setFormatter(ColorFormatter())
    logger.addHandler(ch)
 
def main():
 
    configure_logging()
 
    logging.debug("debug message")
    logging.info("info message")
    logging.warning("warning message")
    logging.error("error message")
    logging.critical("critical message")
 
if __name__ == "__main__":
    main()