python zipfile模块学习笔记

ZIP文件格式是一种常见的存档和压缩标准，这个zipfile模块提供了工具来创建、读取、写入、附加和列出一个ZIP文件。使用ZIP64扩展（即压缩文件大小超过4G），它能解压加密的ZIP文件，解密过程很慢。

1、测试是否为ZIP文件

is_zipfile()函数会返回一个布尔值来表示是否为ZIP文件，代码如下：

#!/usr/bin/python
import zipfile
for filename in ['print_name.py', 'python.zip', 'uwsgi', 'admin']:
    print '%20s %s' % (filename, zipfile.is_zipfile(filename))

如果文件不存在或者不是ZIP文件会返回False。

[root@www home]# python zipfile_is_zipfile.py
       print_name.py False
          python.zip True
               uwsgi False
               admin False

2、读取ZIP文件的内容

#!/usr/bin/env python
import zipfile
                                                                                                      
zf = zipfile.ZipFile('python.zip', 'r')
print zf.namelist()

使用namelist() 函数，返回结果是一个列表

[root@www home]# python zipfile_namelist.py
['test.txt']

#这只能查看ZIP文件的部分内容，使用infolist() 或者 getinfo() 可以从ZIP文件中获取更多信息，代码如下：

import datetime
import zipfile
                                                                                            
def print_info(archive_name):
    zf = zipfile.ZipFile(archive_name)
    for info in zf.infolist():
        print info.filename
        print '\tComment:\t', info.comment
        print '\tModified:\t', datetime.datetime(*info.date_time)
        print '\tSystem:\t\t', info.create_system, '(0 = Windows, 3 = Unix)'
        print '\tZIP version:\t', info.create_version
        print '\tCompressed:\t', info.compress_size, 'bytes'
        print '\tUncompressed:\t', info.file_size, 'bytes'
        print
                                                                                            
if __name__ == '__main__':
    print_info('python.zip')

执行上面代码显示如下结果：

[root@www home]# python zipfile_infolist.py
test.txt
    Comment:   
    Modified:   2013-09-06 20:09:58
    System:     3 (0 = Windows, 3 = Unix)
    ZIP version:    20
    Compressed: 419430400 bytes
    Uncompressed:   419430400 bytes

使用getinfo()函数可以在ZIP文件内查找内容，代码如下：

#!/usr/bin/env python
import zipfile
                                                                                  
zf = zipfile.ZipFile('python.zip')
for filename in ['test.txt', 'notthere.txt']:
    try:
        info = zf.getinfo(filename)
    except KeyError:
        print 'ERROR: Did not find %s in zip file' % filename
    else:
        print "%s is %d bytes" % (info.filename, info.file_size)

如果需要查找的不存在ZIP文档里，会返回一个KeyError错误。

[root@www home]# python zipfile_getinfo.py
test.txt is 419430400 bytes
ERROR: Did not find notthere.txt in zip file

3、从一个ZIP文档中提取文件

#!/usr/bin/env python
import zipfile
                                                                        
zf = zipfile.ZipFile('python.zip')
for filename in ['test.txt', 'notihere.txt']:
    try:
        data = zf.read(filename)
    except KeyError:
        print 'ERROR: Did not find %s in zip file' % filename
    else:
        print filename, ':'
        print repr(data)
    print

要提取的文件会被自动解压：

[root@www home]# python zipfile_read.py
                                                                   
README.txt :
'The examples for the zipfile module use this file and example.zip as data.\n'
                                                                   
ERROR: Did not find notthere.txt in zip file

4、创建一个新的ZIP文件

创建新的ZIP归档文件代码如下：

#!/usr/bin/env python
                                                           
from zipfile_infolist import print_info
import zipfile
                                                           
print 'creating archive'
zf = zipfile.ZipFile('zipfile_write.zip', 'w')
try:
    print 'adding text.txt'
    zf.write('text.txt')
finally:
    print 'closing'
    zf.close()
                                                           
print
print_info('zipfile_write.zip')

默认情况下不会对文件进行压缩：

[root@www home]# python zipfile_write.py
creating archive
adding text.txt
closing
                                                    
text.txt
    Comment:   
    Modified:   2013-09-06 20:39:52
    System:     3 (0 = Windows, 3 = Unix)
    ZIP version:    20
    Compressed: 104857600 bytes
    Uncompressed:   104857600 bytes

如果要对文件进行压缩，zlib模块是必须的，如果zlib可以使用，你可以使用zipfile.ZIP_DEFLATED设置压缩模式为单个文件或者归档一个整体。默认的压缩模式是zipfile.ZIP_STORED。

#!/usr/bin/env python
                                               
from zipfile_infolist import print_info
import zipfile
try:
    import zlib
    compression = zipfile.ZIP_DEFLATED
except:
    compression = zipfile.ZIP_STORED
                                               
modes = { zipfile.ZIP_DEFLATED: 'deflated',
          zipfile.ZIP_STORED:   'stored',
          }
                                               
print 'creating archive'
zf = zipfile.ZipFile('zipfile_write_compression.zip', mode='w')
try:
    print 'adding text.txt with compression mode', modes[compression]
    zf.write('text.txt', compress_type=compression)
finally:
    print 'closing'
    zf.close()
                                               
print
print_info('zipfile_write_compression.zip')

这次文件被压缩：

[root@www home]# python zipfile_write_compression.py
creating archive
adding text.txt with compression mode deflated
closing
                                          
text.txt
    Comment:   
    Modified:   2013-09-06 20:39:52
    System:     3 (0 = Windows, 3 = Unix)
    ZIP version:    20
    Compressed: 101923 bytes
    Uncompressed:   104857600 bytes

替换原始文件名：

#!/usr/bin/env python
                                     
from zipfile_infolist import print_info
import zipfile
                                     
zf = zipfile.ZipFile('zipfile_write_arcname.zip', mode='w')
try:
    zf.write('text.txt', arcname='NOT_README.txt')
finally:
    zf.close()
print_info('zipfile_write_arcname.zip')

结果显示原始文件名已经被替换了：

[root@www home]# python zipfile_write_arcname.py
NOT_README.txt
    Comment:   
    Modified:   2013-09-06 20:39:52
    System:     3 (0 = Windows, 3 = Unix)
    ZIP version:    20
    Compressed: 104857600 bytes
    Uncompressed:   104857600 bytes

更多博文请移步：linux开源技术博客 http://www.chlinux.net

本文参考：http://docs.python.org/2/library/zipfile

         http://pymotw.com/2/zipfile/