python中的logger之二

Rotating-logger

日志檔案太大，一般不容易使用。現在的日志系統一般都提供了友善的日志回繞分片。一般有按照檔案大小、記錄時間長度來對日志檔案分片。

在python logging中，提供了這2種分片方式。

1. 按照檔案大小分片

這種方式使用的Handler是RotatingFileHandler；

class RotatingFileHandler(BaseRotatingHandler):
    """
    Handler for logging to a set of files, which switches from one file
    to the next when the current file reaches a certain size.
    """
    def __init__(self, filename, mode='a', maxBytes=, backupCount=, encoding=None, delay=):
           

下面看看使用方式：

rlogger = logging.getLogger("loggingtest2")
rfh = RotatingFileHandler("log/rtest.log", maxBytes=,backupCount=)

formatter = logging.Formatter('%(name)-12s %(asctime)s.%(msecs)03d %(levelname)-8s %(message)s', datefmt='%Y-%m-%d,%H:%M:%S')  
rfh.setFormatter(formatter)

rlogger.addHandler(rfh)
           

完整示例：

import sys,time
import logging
from logging.handlers import RotatingFileHandler,TimedRotatingFileHandler

rlogger = logging.getLogger("loggingtest2")
rfh = RotatingFileHandler("log/rtest.log", maxBytes=,backupCount=)

formatter = logging.Formatter('%(name)-12s %(asctime)s.%(msecs)03d %(levelname)-8s %(message)s', datefmt='%Y-%m-%d,%H:%M:%S')  
rfh.setFormatter(formatter)

rlogger.addHandler(rfh)

rlogger.setLevel(level = logging.INFO)

i = 
while i<:
    rlogger.info("this is a %s %i.......","info",i)
    rlogger.warning("this is a %s %i........", "warning",i)
    i=i+

           

執行時，會在log下生成rtest.log，以及分片的3個backup檔案rtest.log.0, rtest.log.1, rtest.log.2

1. 按照時間長度分片

這裡使用的是TimedRotatingFileHandler。

定義如下：

class TimedRotatingFileHandler(BaseRotatingHandler):
    """
    Handler for logging to a file, rotating the log file at certain timed
    intervals.

    If backupCount is > 0, when rollover is done, no more than backupCount
    files are kept - the oldest ones are deleted.
    """
    def __init__(self, filename, when='h', interval=, backupCount=, encoding=None, delay=False, utc=False):
           

使用方式：

formatter = logging.Formatter('%(name)-12s %(asctime)s.%(msecs)03d %(levelname)-8s %(message)s', datefmt='%Y-%m-%d,%H:%M:%S')  

trlogger = logging.getLogger()
trfh = TimedRotatingFileHandler("log/tr_test.log",when="S",interval=,backupCount=)

trfh.setFormatter(formatter)
trlogger.addHandler(trfh)
           

完整示例：

import sys,time
import logging
from logging.handlers import RotatingFileHandler,TimedRotatingFileHandler


formatter = logging.Formatter('%(name)-12s %(asctime)s.%(msecs)03d %(levelname)-8s %(message)s', datefmt='%Y-%m-%d,%H:%M:%S')  

trlogger = logging.getLogger()
trfh = TimedRotatingFileHandler("log/tr_test.log",when="S",interval=,backupCount=)

trfh.setFormatter(formatter)
trlogger.addHandler(trfh)

trlogger.setLevel(level = logging.INFO)

i=
while i < :
    trlogger.info("this is a %s .......","info")
    trlogger.warning("this is a %s........", "warning")
    time.sleep(.)
    i=i+