问题：

假设我们自己写了一个名为 log_config.py 的日志记录程序模块。此模块会被其他程序所引用，如下例子。

import log_config

logger = log_config.log_config("./test_log.txt", "tester")

logger.info("log start.")

logger.info("something happens")

logger.info("log end.")

解决方法：

先看一下目前系统中的Python 路径情况：

Python 2.7.6 (default, Jun 22 2015, 17:58:13)

[GCC 4.8.2] on linux2

Type "help", "copyright", "credits" or "license" for more information.

>>> import sys

>>> print sys.path

['', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-x86_64-linux-gnu', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages']

结果显示，在这几个目录都是 Python 的系统目录。我们的模块可以放在如下二个目录即可。

'/usr/local/lib/python2.7/dist-packages',

'/usr/lib/python2.7/dist-packages'

更进一步：

如果自定义的模块不想与Python 系统的模块放在同一目录下，可以在上面二个目录中增加一个路径文件 user_defined_modules.pth 。此文件内容就是我们自定义模块的存放路径。例子如下：

/home/tom/python_modules/

在 /home/tom/python_module/ 目录中把我们的模块文件 log_config.py 存放好即可。

附录 log_config.py 源码：

此代码可以设置日志文件的生成规则，目录设置的是 1 小时 1 个文件。如果一小时内单个文件大小超过 10 MB会自动分割成多个文件。

#!/usr/bin/python

# encoding=utf-8

#example

#import log_config

#logger = log_config.log_config("./test_log.txt", "tester")

#logger.info("log start")

#logger.info("log end")

#!/usr/bin/env python

# -*- coding:utf-8 -*

""" Setup a Logger which creates a new log file when it

reach up to it limits, such as one hour and file size 10 MB.

"""

__author__ = "Zhiwei Yan"

__copyright__ = "Copyright 2016, The Common tools Project"

__credits__ = ["Zhiwei Yan"]

__license__ = "Apache License"

__version__ = "2.0"

__maintainer__ = "Zhiwei YAN"

__email__ = "jerod.yan@gmail.com"

__status__ = "Production"

import logging

import logging.handlers as handlers

import time, datetime

class SizedTimedRotatingFileHandler(handlers.TimedRotatingFileHandler):

"""

Handler for logging to a set of files, which switches from one file

to the next when the current file reaches a certain size, or at certain

timed intervals

"""

def __init__(self, filename, mode='a', maxBytes=0, backupCount=0, encoding=None,

delay=0, when='h', interval=1, utc=False):

# If rotation/rollover is wanted, it doesn't make sense to use another

# mode. If for example 'w' were specified, then if there were multiple

# runs of the calling application, the logs from previous runs would be

# lost if the 'w' is respected, because the log file would be truncated

# on each run.

if maxBytes > 0:

mode = 'a'

handlers.TimedRotatingFileHandler.__init__(

self, filename, when, interval, backupCount, encoding, delay, utc)

self.maxBytes = maxBytes

def shouldRollover(self, record):

"""

Determine if rollover should occur.

Basically, see if the supplied record would cause the file to exceed

the size limit we have.

"""

if self.stream is None: # delay was set...

self.stream = self._open()

if self.maxBytes > 0: # are we rolling over?

msg = "%s\n" % self.format(record)

self.stream.seek(0, 2) #due to non-posix-compliant Windows feature

if self.stream.tell() + len(msg) >= self.maxBytes:

return 1

t = int(time.time())

if t >= self.rolloverAt:

return 1

return 0

def log_config(log_filename, logger_str):

logging.basicConfig(format = "%(asctime)s" "[%(module)s:%(funcName)s:%(lineno)d]\n" "%(message)s \n")

logger=logging.getLogger(logger_str)

logger.propagate = False

logger.setLevel(logging.DEBUG)

handler=SizedTimedRotatingFileHandler(

log_filename,

maxBytes=10*1024*1024, backupCount=24*30,

when='h',interval=1,

# encoding='bz2', # uncomment for bz2 compression

)

logformatter = logging.Formatter("%(asctime)s" "[%(module)s:%(funcName)s:%(lineno)d]\n" "%(message)s \n")

handler.setFormatter(logformatter)

logger.addHandler(handler)

return logger