python中zlib模块实例应用

fdeli

　　python中zlib模块的实例应用。
　　zlib模块是用来压缩或者解压缩数据，以便保存和传输。它是其他压缩工具的基础。下面是两段代码：
　　第一个是用来压缩数据并保存到本地磁盘：

#!/usr/bin/python
#-*-coding:UTF-8 -*-
import zlib
import sys

compressor = zlib.compressobj(1)
filein = raw_input('please input the filename: ')
fileout = raw_input('please input the compressed filename: ')
try:
fdin = open(filein,'r')
except IOError:
print 'open %s failed!!!',filein
sys.exit(1)

fdout = open(fileout,'wb')
while True:
block = fdin.read(64)
if not block :
break
compressed = compressor.compress(block)
fdout.write(compressed)
remaining = compressor.flush()
fdout.write(remaining)
print 'compressed: %s' % filein

　　
　　第二段，是用来解压数据并保存到本地磁盘：

#!/usr/bin/python
#-*- coding UTF-8 -*-
import zlib
import sys

filein = raw_input('please input the compressed filename: ')
fileout = raw_input('please input the output filename: ')
try:
fdin = open(filein,'rb')
except IOError:
print 'open %s failed!!!' % filein
sys.exit(1)

fdout = open(fileout,'w')
decompressor = zlib.decompressobj()
while True:
block = fdin.read(128)
if not block:
break
to_de = decompressor.unconsumed_tail + block
decompressed = decompressor.decompress(to_de)
fdout.write(decompressed)

remaining = decompressor.flush()
fdout.write(remaining)
print 'decompressed'

　　
　　下面是实验实验过程：

[iyunv@localhost tmp]# tar -cf etc.tar /etc
tar: Removing leading `/' from member names
[iyunv@localhost tmp]# ls
etc.tar  ipvsadm-1.24  keepalived-1.1.19  zlib_compressobj.py  zlib_decompressobj.py
[iyunv@localhost tmp]# ./zlib_compressobj.py
please input the filename: /tmp/etc.tar
please input the compressed filename: /tmp/etc.tar.zlib
compressed: /tmp/etc.tar
[iyunv@localhost tmp]# du -h etc.tar
19Metc.tar
[iyunv@localhost tmp]# du -h etc.tar.zlib
6.6Metc.tar.zlib
[iyunv@localhost tmp]# ./zlib_decompressobj.py
please input the compressed filename: /tmp/etc.tar.zlib
please input the output filename: /tmp/etc.tar1
decompressed
[iyunv@localhost tmp]# du -h etc.tar1
19Metc.tar1
[iyunv@localhost tmp]# tar -xf etc.tar1
[iyunv@localhost tmp]# ls
etc      etc.tar1      ipvsadm-1.24       zlib_compressobj.py
etc.tar  etc.tar.zlib  keepalived-1.1.19  zlib_decompressobj.py
[iyunv@localhost tmp]# cd etc
[iyunv@localhost etc]# du -sh .
21M.
[iyunv@localhost etc]# du -sh /etc
21M/etc
[iyunv@localhost etc]#