clogger.py

#coding: utf-8

import logging
from logging import StreamHandler


class ColorizingStreamHandler(StreamHandler):
    color_map = {
        'black': 0,
        'red': 1,
        'green': 2,
        'yellow': 3,
        'blue': 4,
        'magenta': 5,
        'cyan': 6,
        'white': 7,
    }

    #: level to (bg, fg, bold/intense)
    level_map = {
            logging.DEBUG: (None, None, False),
            logging.INFO: (None, 'green', False),
            logging.WARNING: (None, 'yellow', True),
            logging.ERROR: (None, 'red', True),
            logging.CRITICAL: ('red', 'white', True),
    }

    csi = '\x1b['
    reset = '\x1b[0m'

    @property
    def is_tty(self):
        isatty = getattr(self.stream, 'isatty', None)
        return isatty and isatty()

    def format(self, record):
        message = StreamHandler.format(self, record)
        if self.is_tty:
            parts = message.split('\n', 1)
            parts[0] = self.colorize(parts[0], record)
            message = '\n'.join(parts)
        return message

    def colorize(self, message, record):
        if record.levelno in self.level_map:
            bg, fg, bold = self.level_map[record.levelno]
            params = []
            if bg in self.color_map:
                params.append(str(self.color_map[bg] + 40))
            if fg in self.color_map:
                params.append(str(self.color_map[fg] + 30))
            if bold:
                params.append('1')
            if params:
                message = ''.join((self.csi, ';'.join(params), 'm', message,
                                   self.reset))
        return message