python中zip和unzip数据的方法

yipeiwu_com6年前Python基础

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。

相关文章

python概率计算器实例分析

本文实例讲述了python概率计算器实现方法。分享给大家供大家参考。具体实现方法如下: from random import randrange #randrange form ra...

python cv2读取rtsp实时码流按时生成连续视频文件方式

python cv2读取rtsp实时码流按时生成连续视频文件方式

我就废话不多说了,直接上代码吧! # coding: utf-8 import datetime import cv2 import os ip = '192.168.3.160...

Python的Twisted框架上手前所必须了解的异步编程思想

Python的Twisted框架上手前所必须了解的异步编程思想

前言 最近有人在Twisted邮件列表中提出诸如"为任务紧急的人提供一份Twisted介绍"的需求。值得提前透露的是,这个系列并不会如他们所愿。尤其是介绍Twisted框架和基于Pyth...

pytorch 中pad函数toch.nn.functional.pad()的用法

pytorch 中pad函数toch.nn.functional.pad()的用法

padding操作是给图像外围加像素点。 为了实际说明操作过程,这里我们使用一张实际的图片来做一下处理。 这张图片是大小是(256,256),使用pad来给它加上一个黑色的边框。具体代...

python基础教程之自定义函数介绍

函数最重要的目的是方便我们重复使用相同的一段程序。 将一些操作隶属于一个函数,以后你想实现相同的操作的时候,只用调用函数名就可以,而不需要重复敲所有的语句。 函数的定义 首先,我们要定义...