使用zlib进行压缩解压

时间：2010-08-25 来源：bigluo

A:如何使用zlib模块来进行压缩解压了？
Q:
1.使用zlib.compress可以压缩字符串。使用zlib.decompress可以解压字符串。
压缩解压字符串示范代码:

import zlib
message = 'witch which has which witches wrist watch'
compressed = zlib.compress(message)
decompressed = zlib.decompress(compressed)
print 'original:', repr(message)
print 'compressed:', repr(compressed)
print 'decompressed:', repr(decompressed)

输出

original: 'witch which has which witches wrist watch'
compressed: 'x\x9c+\xcf,I\xceP(\xcf\xc8\x04\x92\x19\x89\xc5PV9H4\x15\xc8+\xca,.Q(O\x04\xf2\x00D?\x0f\x89'
decompressed: 'witch which has which witches wrist watch'

2.使用zlib.compressobj和zlib.decompressobj比较适合用于对文件进行压缩解压。
以下定义的两个函数可以做为使用zlib.compressobj和zlib.decompressobj对文件进行压缩解压的例子:

def compress(infile, dst, level=9):
infile = open(infile, 'rb')
dst = open(dst, 'wb')
compress = zlib.compressobj(level)
data = infile.read(1024)
while data:
dst.write(compress.compress(data))
data = infile.read(1024)
dst.write(compress.flush())
def decompress(infile, dst):
infile = open(infile, 'rb')
dst = open(dst, 'wb')
decompress = zlib.decompressobj()
data = infile.read(1024)
while data:
dst.write(decompress.decompress(data))
data = infile.read(1024)
dst.write(decompress.flush())