python 一个改进的LOGGER类

此logger改进的目的有两个：

1. 默认python库中的logging.handlers.TimedRotatingFileHandler会在logger初始化阶段不生成suffix，这样一旦程序重启就会导致上次启动的日志被覆盖。

1. 定制log目录、名称，调用log更简单易用，并让其支持自动创建log目录。

# -*- coding: utf-8 -*-
"""
 
auth:   jaypei
email:  [email protected]
 
例程：
from somelib import logger
 
# 默认log存放目录,需要在程序入口调用才能生效,可省略
logger.log_dir = "./app"
# log文件名前缀,需要在程序入口调用才能生效,可省略
logger.log_name = "test_log"
 
conf = logger.Logger()
conf.debug('debug')
conf.warn('tr-warn')
conf.info('ds-info')
conf.error('ss-error')
 
"""
 
import os, time, threading
import datetime
import logging
import logging.handlers
try:
    import codecs
except ImportError:
    codecs = None
 
log_dir = "log"
log_name = "applog"
 
_logger_init_lock = threading.Lock()
 
class MyHandler(logging.handlers.TimedRotatingFileHandler):
    """
    自己定义的TimedRotatingFileHandler
    """
    def __init__(self, log_dir, file_name_prefix):
        self.log_dir = log_dir
        self.file_name_prefix = file_name_prefix
 
        self._mkdirs()
 
        self.baseFilename = "%s.%s.log" % (os.path.join(self.log_dir, file_name_prefix),
                time.strftime("%Y%m%d"))
 
        logging.handlers.TimedRotatingFileHandler.__init__(self,
                self.baseFilename,
                when='midnight', interval=1,
                backupCount=0, encoding=None)
 
    def doRollover(self):
        self.stream.close()
        # get the time that this sequence started at and make it a TimeTuple
        t = self.rolloverAt - self.interval
        timeTuple = time.localtime(t)
        self.baseFilename = "%s.%s.log" % (os.path.join(self.log_dir, self.file_name_prefix),
                time.strftime("%Y%m%d"))
        if self.encoding:
            self.stream = codecs.open(self.baseFilename, 'a', self.encoding)
        else:
            self.stream = open(self.baseFilename, 'a')
        self.rolloverAt = self.rolloverAt + self.interval
 
    def _mkdirs(self):
        if not os.path.exists(self.log_dir):
            try:
                os.makedirs(self.log_dir)
            except Exception,e:
                print str(e)
 
class Logger(object):
    __instance = None
 
    def __new__(classtype, *args, **kwargs):
        _logger_init_lock.acquire()
        if classtype != type(classtype.__instance):
            classtype.__instance = object.__new__(classtype, *args, **kwargs)
            classtype.__instance.init()
 
        _logger_init_lock.release()
        return classtype.__instance
 
    def init(self):
        # 创建日志目录
        global log_dir, log_name
        self.log_dir = log_dir
        self.log_name = log_name
 
        self.is_debug = True
        self.is_info = True
        self.is_warn = True
        self.is_error = True
 
        self.logger_formatter = "[%(asctime)-15s,%(levelname)s] %(message)s"
        self.file_formatter = "[%(asctime)-15s,%(levelname)s] %(message)s"
        self._initLogger()
 
    def _initLogger(self):
        # 初始化logger
        logging.basicConfig(format=self.logger_formatter)
        self.logger = logging.getLogger("_sys")
        self.logger.setLevel(logging.DEBUG)
 
        # info、warn、error都放到info文件
        # error单独放到error文件
        for t in (("info", logging.INFO),
                ("error", logging.ERROR)):
 
            filehandler = MyHandler(self.log_dir,
                    "%s.%s" % (self.log_name, t[0]))
            filehandler.suffix = "%Y%m%d.log"
            filehandler.setLevel(t[1])
            filehandler.setFormatter(logging.Formatter(self.file_formatter))
            self.logger.addHandler(filehandler)
 
        # debug 单独放到debug文件
        filehandler = MyHandler(self.log_dir,
                "%s.debug" % self.log_name)
        filehandler.suffix = "%Y%m%d.log"
        filehandler.setLevel(logging.DEBUG)
        filehandler.setFormatter(logging.Formatter(self.file_formatter))
        self.logger.addHandler(filehandler)
 
    def getLogger(self):
        return self.logger
 
    def debug(self, msg):
        if self.is_debug:
            self.logger.debug(msg)
 
    def info(self, msg):
        if self.is_info:
            self.logger.info(msg)
 
    def warn(self, msg):
        if self.is_warn:
            self.logger.warn(msg)
 
    def error(self, msg):
        if self.is_error:
            self.logger.error(msg)
 
def info(msg):
    Logger().info(msg)
 
def warn(msg):
    Logger().warn(msg)
 
def debug(msg):
    Logger().debug(msg)
 
def error(msg):
    Logger().error(msg)

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