Adds a colorizing stream handler..

logger.py

# -*- coding: utf-8 -*-
"""logging.py: Django www"""

import ctypes
import logging
import platform
import os

__author__ = 'Steven Klass'
__date__ = '2/24/12 10:20 PM'
__credits__ = ['Vinay Sajip', 'Steven Klass']


class LevelLTEInfo(logging.Filter):
    """Just filter everything <= INFO"""
    def filter(self, record):
        """Determine if the specified record is to be logged.
        :param record: record
        """
        return record.levelno <= logging.INFO


class ManagementExclude(logging.Filter):
    """Filter out management commands"""
    def filter(self, record):
        """Determine if the specified record is to be logged.
        :param record: record
        """
        return record.name.split(".")[-1] != "management"


class ColorizingStreamHandler(logging.StreamHandler):
    """A handler class which writes colored logging records, appropriately formatted, to a stream.
    Note that this class does not close the stream, as sys.stdout or sys.stderr may be used.
    """

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

    #levels to (background, foreground, bold/intense)
    if os.name == 'nt':
        level_map = {
            logging.DEBUG: (None, 'blue', True),
            logging.INFO: (None, 'white', False),
            logging.WARNING: (None, 'yellow', True),
            logging.ERROR: (None, 'red', True),
            logging.CRITICAL: ('red', 'white', True),
        }
    else:
        level_map = {
            logging.DEBUG: (None, 'cyan', False),
            logging.INFO: (None, 'black', False),
            logging.WARNING: (None, 'yellow', False),
            logging.ERROR: (None, 'red', False),
            logging.CRITICAL: ('red', 'white', True),
        }
    if os.getenv('DJANGO_COLORS') == 'dark':
        level_map[logging.INFO] = (None, 'white', False)
    csi = '\x1b['
    reset = '\x1b[0m'

    @property
    def is_tty(self):
        """Are we a tty"""
        if (hasattr(self.stream, "isatty") and self.stream.isatty()) \
           or os.environ.get('TERM') == 'ANSI' or os.environ.get('PYCHARM_HOSTED'):
            if platform.system() == 'Windows' and not os.environ.get('TERM') == 'ANSI':
                return False
            else:
                return True
        else:
            return False

    def emit(self, record):
        """Emit a record.
        :param record: The record element.
        """
        try:
            message = self.format(record)
            stream = self.stream
            if not self.is_tty:
                stream.write(message)
            else:
                self.output_colorized(message)
            stream.write(getattr(self, 'terminator', '\n'))
            self.flush()
        except (KeyboardInterrupt, SystemExit):
            raise
        except:
            self.handleError(record)

    if os.name != 'nt':
        def output_colorized(self, message):
            """Output color
            :param message: message to be colored.
            """
            self.stream.write(message)
    else:
        import re
        ansi_esc = re.compile(r'\x1b\[((?:\d+)(?:;(?:\d+))*)m')

        nt_color_map = {
            0: 0x00,    # black
            1: 0x04,    # red
            2: 0x02,    # green
            3: 0x06,    # yellow
            4: 0x01,    # blue
            5: 0x05,    # magenta
            6: 0x03,    # cyan
            7: 0x07,    # white
        }

        def output_colorized(self, message):
            """Colorize the ouput
            :param message: The message to be colored.
            """
            parts = self.ansi_esc.split(message)
            write = self.stream.write
            h = None
            fd = getattr(self.stream, 'fileno', None)
            if fd is not None:
                fd = fd()
                if fd in (1, 2):  # stdout or stderr
                    h = ctypes.windll.kernel32.GetStdHandle(-10 - fd)
            while parts:
                text = parts.pop(0)
                if text:
                    write(text)
                if parts:
                    params = parts.pop(0)
                    if h is not None:
                        params = [int(p) for p in params.split(';')]
                        color = 0
                        for p in params:
                            if 40 <= p <= 47:
                                color |= self.nt_color_map[p - 40] << 4
                            elif 30 <= p <= 37:
                                color |= self.nt_color_map[p - 30]
                            elif p == 1:
                                color |= 0x08  # foreground intensity on
                            elif p == 0:       # reset to default color
                                color = 0x07
                            else:
                                pass  # error condition ignored
                        ctypes.windll.kernel32.SetConsoleTextAttribute(h, color)

    def colorize(self, message, record):
        """Colorize the output.
        :param record: The record
        :param message: The message
        """
        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

    def format(self, record):
        """Format this output
        :param record: The record
        """
        message = logging.StreamHandler.format(self, record)
        if self.is_tty:
            # Don't colorize any traceback
            parts = message.split('\n', 1)
            parts[0] = self.colorize(parts[0], record)
            message = '\n'.join(parts)
        return message