24.自定义python日志handler

功能

可实现日志打印在控制台的同时，输出到文件中
且文件根据%Y%m%d或者%Y%m%d%H自动决定按天还是按小时分割
代码比较简单，比直接用自带的方便一些

代码

import sys
import traceback

import os as _os
import logging as _logging
import time as _time
import threading as _threading


_file_lock = _threading.RLock()
class DateRotatingFileHandler(_logging.StreamHandler):
    """
    按天分片的LogHandler
    """
    def __init__(self, file_path, surfix="%Y%m%d%H"):
        """
        :param file_path: 日志路径(不含后缀)
        :type file_path: str
        :param surfix: 时间后缀, 可以使用python的dateformat参数. 默认为%Y%m%d%H
        :type surfix: str
        """
        _logging.StreamHandler.__init__(self)
        self.stream = None
        self._filePath = file_path
        self._surfix = surfix
        _file_lock.acquire()
        try:
            if _os.path.exists(self._filePath):
                mtime = _os.stat(self._filePath).st_mtime
                d_fmt = _time.strftime(self._surfix, _time.localtime(mtime))
                self.stream = open(_os.path.join(self._filePath), "a")
                self._currentSurfix = d_fmt
            else:
                self._currentSurfix = ""
        finally:
            _file_lock.release()
        self.setFormatter(_logging.Formatter("%(asctime)s [%(levelname)s]\t%(message)s", "%Y-%m-%d %H:%M:%S"))

    def _checkFile(self, ts):
        d_fmt = _time.strftime(self._surfix, _time.localtime(ts))
        if d_fmt != self._currentSurfix:
            _file_lock.acquire()
            try:
                if not self.stream is None:
                    self.flush()
                    self.stream.close()
                    _os.rename(self._filePath, self._filePath + "." + self._currentSurfix)
                self.stream = open(_os.path.join(self._filePath), "a")
                self._currentSurfix = d_fmt
            finally:
                _file_lock.release()

    def emit(self, record):
        self._checkFile(record.created)
        msg = self.format(record)
        sys.stdout.write(msg+"\n")
        sys.stdout.flush()
        _logging.StreamHandler.emit(self, record)

    def flush(self):
        if self.stream and hasattr(self.stream, "flush") and not self.stream.closed:
            _logging.StreamHandler.flush(self)

    def writeRAW(self, line):
        self._checkFile(_time.time())
        self.stream.write(line)
        self.stream.flush()

    def close(self):
        super(DateRotatingFileHandler, self).close()
        if not self.stream is None:
            try:
                self.stream.close()
            except:
                traceback.print_exc()

h = DateRotatingFileHandler("./pg.log")
formatter = _logging.Formatter('\033[33m%(asctime)s - %(process)d - %(threadName)s - %(name)s - %(levelname)s - %(filename)s:%(lineno)d - %(funcName)s - %(message)s\033[0m')
h.setFormatter(formatter)
logger = _logging.getLogger("[TEST]")
logger.setLevel(_logging.DEBUG)
logger.handlers.clear()
logger.addHandler(h)
logger.info("tttttttttttt")

逻辑说明

• 生成pg.log文件
• 第二天的时候将pg.log重命名为 pg.log.%Y%m%d （%Y%m%d）
• 依次类推