python中zip和unzip数据的方法


            本文实例讲述了python zip和unzip数据的方法。分享给大家供大家参考。具体实现方法如下：





# zipping and unzipping a string using the zlib module

# a very large string could be zipped and saved to a file speeding up file writing time 

# and later reloaded and unzipped by another program speeding up reading of the file

# tested with Python24   vegaseat   15aug2005

import zlib

str1 = \

"""Dallas Cowboys football practice at Valley Ranch was delayed on Wednesday 

for nearly two hours. One of the players, while on his way to the locker

room happened to look down and notice a suspicious looking, unknown white

powdery substance on the practice field.

The coaching staff immediately suspended practice while the FBI was

called in to investigate. After a complete field analysis, the FBI

determined that the white substance unknown to the players was the goal

line.

Practice was resumed when FBI Special Agents decided that the team would not

be likely to encounter the substance again.

"""

print '-'*70 # 70 dashes for the fun of it

print str1

print '-'*70

crc_check1 = zlib.crc32(str1)

print "crc before zip=", crc_check1

print "Length of original str1 =", len(str1)

# zip compress the string

zstr1 = zlib.compress(str1)

print "Length of zipped str1 =", len(zstr1)

filename = 'Dallas.zap'

# write the zipped string to a file

fout = open(filename, 'w')

try:

  print >> fout, zstr1

except IOError:

  print "Failed to open file..."

else:

  print "done writing", filename

fout.close()

# read the zip file back

fin = open(filename, 'r')

try:

  zstr2 = fin.read()

except IOError:

  print "Failed to open file..."

else:

  print "done reading", filename

fin.close()

# unzip the zipped string from the file

str2 = zlib.decompress(zstr2)

print '-'*70

print str2

print '-'*70

crc_check2 = zlib.crc32(str2)

print "crc after unzip =", crc_check2, "(check sums should match)"







希望本文所述对大家的Python程序设计有所帮助。