python压缩文件的效率高吗？

#-*- coding: utf-8 -*-

#!/usr/bin/evn python

"""

USAGE:

        Bak_rsync_Python.py version

"""

import sys

import time

import os

import shutil

import subprocess

import tarfile

rundir=os.getcwd()

src_dir='/data/rsync_center'

bak_dir='/data/backup/game/test'

today=time.strftime("%Y_%m_%d", time.localtime())

def main(version):

        #set local var

        md5="/sbin/md5"

        bak_file="rsync_center_"+today+"_"+version+".tgz" #多个变量联合做变量

        md5_file=rundir+"/md5/"+bak_file+".md5"

        cmd="%s %s > %s" % (md5,bak_file,md5_file)    

        #print bak_file

        #print md5_file

        #tar src dir

        os.chdir(src_dir)

        tar=tarfile.open(bak_file,'w|gz')

        tar.add(src_dir)

        tar.close()

        #tgz file md5

        ret=subprocess.call(cmd,shell=True) #subprocess.call返回值是退出状态

        if ret !=0:             

                print "md5 failed"

                sys.exit(1)

        #else: print ret

        #move tgz to dst dir

        shutil.move(bak_file,bak_dir)

if __name__=='__main__':

        try:

                len(sys.argv)!=2

        except:

                print "Please give version"

                print __doc__

        else:

                print "start at",time.ctime()

                version=sys.argv[1]

                main(version)

                print "end at",time.ctime()

#!/bin/sh -

# Bak_rsync_Shell.sh version

shell_dir=`pwd`

src_dir=/data/rsync_center

bak_dir="/data/backup/game/test"

log_file=${shell_dir}/rsync_center_bak.log

Version=$1

Today=`/bin/date +%Y_%m_%d`

Fourteenday=`/bin/date -v -8d +%Y_%m_%d`

bak_file="rsync_center_${Today}_${Version}.tgz"

md5_file=${shell_dir}/md5/$bak_file.md5

if [ $# -ne 1 ]

        then    echo "Please give a version!"

                break

else

        startdate=`date "+%Y-%m-%d %H:%M:%S"`

        echo "rsync_center backup Start  at " $startdate

        cd $src_dir

        tar -zcf $bak_file ./

        /sbin/md5 $bak_file > $md5_file

        mv $bak_file $bak_dir/

        enddate=`date "+%Y-%m-%d %H:%M:%S"`

        echo "rsync_center backup Complete at" $enddate

fi

#du -sh /data/rsync_center/

112M    /data/rsync_center/

#sh Bak_rsync_Shell.sh testShell

rsync_center backup Start  at  2012-03-15 14:53:37

tar: ./rsync_center_2012_03_15_testShell.tgz: Can't add archive to itself

rsync_center backup Complete at 2012-03-15 14:53:46

#python Bak_rsync_Python.py testPython

start at Thu Mar 15 14:54:54 2012

end at Thu Mar 15 14:55:20 2012

#ll -h /data/backup/game/test/ | awk '{print$5,$9}'

49M rsync_center_2012_03_15_testPython.tgz

49M rsync_center_2012_03_15_testShell.tgz