#!/usr/local/python/bin

 # coding=utf-8

 '''Implements a simple log library.

 This module is a simple encapsulation of logging module to provide a more

 convenient interface to write log. The log will both print to stdout and

 write to log file. It provides a more flexible way to set the log actions,

 and also very simple. See examples showed below:

 Example 1: Use default settings

     import log

     log.debug('hello, world')

     log.info('hello, world')

     log.error('hello, world')

     log.critical('hello, world')

 Result:

 Print all log messages to file, and only print log whose level is greater

 than ERROR to stdout. The log file is located in '/tmp/xxx.log' if the module

 name is xxx.py. The default log file handler is size-rotated, if the log

 file's size is greater than 20M, then it will be rotated.

 Example 2: Use set_logger to change settings

     # Change limit size in bytes of default rotating action

     log.set_logger(limit = 10240) # 10M

     # Use time-rotated file handler, each day has a different log file, see

     # logging.handlers.TimedRotatingFileHandler for more help about 'when'

     log.set_logger(when = 'D', limit = 1)

     # Use normal file handler (not rotated)

     log.set_logger(backup_count = 0)

     # File log level set to INFO, and stdout log level set to DEBUG

     log.set_logger(level = 'DEBUG:INFO')

     # Both log level set to INFO

     log.set_logger(level = 'INFO')

     # Change default log file name and log mode

     log.set_logger(filename = 'yyy.log', mode = 'w')

     # Change default log formatter

     log.set_logger(fmt = '[%(levelname)s] %(message)s'

 '''

 __author__ = "tuantuan.lv <dangoakachan@foxmail.com>"

 __status__ = "Development"

 __all__ = ['set_logger', 'debug', 'info', 'warning', 'error',

            'critical', 'exception']

 import os

 import sys

 import logging

 import logging.handlers

 # Color escape string

 COLOR_RED='\033[1;31m'

 COLOR_GREEN='\033[1;32m'

 COLOR_YELLOW='\033[1;33m'

 COLOR_BLUE='\033[1;34m'

 COLOR_PURPLE='\033[1;35m'

 COLOR_CYAN='\033[1;36m'

 COLOR_GRAY='\033[1;37m'

 COLOR_WHITE='\033[1;38m'

 COLOR_RESET='\033[1;0m'

 # Define log color

 LOG_COLORS = {

     'DEBUG': '%s',

     'INFO': COLOR_GREEN + '%s' + COLOR_RESET,

     'WARNING': COLOR_YELLOW + '%s' + COLOR_RESET,

     'ERROR': COLOR_RED + '%s' + COLOR_RESET,

     'CRITICAL': COLOR_RED + '%s' + COLOR_RESET,

     'EXCEPTION': COLOR_RED + '%s' + COLOR_RESET,

 }

 # Global logger

 g_logger = None

 class ColoredFormatter(logging.Formatter):

     '''A colorful formatter.'''

     def __init__(self, fmt = None, datefmt = None):

         logging.Formatter.__init__(self, fmt, datefmt)

     def format(self, record):

         level_name = record.levelname

         msg = logging.Formatter.format(self, record)

         return LOG_COLORS.get(level_name, '%s') % msg

 def add_handler(cls, level, fmt, colorful, **kwargs):

     '''Add a configured handler to the global logger.'''

     global g_logger

     if isinstance(level, str):

         level = getattr(logging, level.upper(), logging.DEBUG)

     handler = cls(**kwargs)

     handler.setLevel(level)

     if colorful:

         formatter = ColoredFormatter(fmt)

     else:

         formatter = logging.Formatter(fmt)

     handler.setFormatter(formatter)

     g_logger.addHandler(handler)

     return handler

 def add_streamhandler(level, fmt):

     '''Add a stream handler to the global logger.'''

     return add_handler(logging.StreamHandler, level, fmt, True)

 def add_filehandler(level, fmt, filename , mode, backup_count, limit, when):

     '''Add a file handler to the global logger.'''

     kwargs = {}

     # If the filename is not set, use the default filename

     if filename is None:

         filename = getattr(sys.modules['__main__'], '__file__', 'log.py')

         filename = os.path.basename(filename.replace('.py', '.log'))

         filename = os.path.join('/tmp', filename)

     kwargs['filename'] = filename

     # Choose the filehandler based on the passed arguments

     if backup_count == 0: # Use FileHandler

         cls = logging.FileHandler

         kwargs['mode' ] = mode

     elif when is None:  # Use RotatingFileHandler

         cls = logging.handlers.RotatingFileHandler

         kwargs['maxBytes'] = limit

         kwargs['backupCount'] = backup_count

         kwargs['mode' ] = mode

     else: # Use TimedRotatingFileHandler

         cls = logging.handlers.TimedRotatingFileHandler

         kwargs['when'] = when

         kwargs['interval'] = limit

         kwargs['backupCount'] = backup_count

     return add_handler(cls, level, fmt, False, **kwargs)

 def init_logger():

     '''Reload the global logger.'''

     global g_logger

     if g_logger is None:

         g_logger = logging.getLogger()

     else:

         logging.shutdown()

         g_logger.handlers = []

     g_logger.setLevel(logging.DEBUG)

 def set_logger(filename = None, mode = 'a', level='ERROR:DEBUG',

                fmt = '[%(levelname)s] %(asctime)s %(message)s',

                backup_count = 5, limit = 20480, when = None):

     '''Configure the global logger.'''

     level = level.split(':')

     if len(level) == 1: # Both set to the same level

         s_level = f_level = level[0]

     else:

         s_level = level[0]  # StreamHandler log level

         f_level = level[1]  # FileHandler log level

     init_logger()

     add_streamhandler(s_level, fmt)

     add_filehandler(f_level, fmt, filename, mode, backup_count, limit, when)

     # Import the common log functions for convenient

     import_log_funcs()

 def import_log_funcs():

     '''Import the common log functions from the global logger to the module.'''

     global g_logger

     curr_mod = sys.modules[__name__]

     log_funcs = ['debug', 'info', 'warning', 'error', 'critical',

                  'exception']

     for func_name in log_funcs:

         func = getattr(g_logger, func_name)

         setattr(curr_mod, func_name, func)

 # Set a default logger

 set_logger()