阅读zlib档案列表

Question

我有一个文件，其中包含许多zlib档案本身。该文件的 结构如下：

+-------------------------+ 
|+-----------------------+| 
||  CMF+FLG (78DA) || 
|+-----------------------+| 
|+-----------------------+| 
||...compressed data 1...|| 
|+-----------------------+| 
|+-----------------------+| 
||  ADLER32  || 
|+-----------------------+| 
| 
|+-----------------------+| 
||  CMF+FLG (78DA) || 
|+-----------------------+| 
|+-----------------------+| 
||...compressed data 2...|| 
|+-----------------------+| 
|+-----------------------+| 
||  ADLER32  || 
|+-----------------------+| 
| 
|+-----------------------+| 
||  CMF+FLG (78DA) || 
|+-----------------------+| 
|+-----------------------+| 
||...compressed data 3...|| 
|+-----------------------+| 
|+-----------------------+| 
||  ADLER32  || 
|+-----------------------+| 
|       | 
|.........................| 
|       | 
|+-----------------------+| 
||  CMF+FLG (78DA) || 
|+-----------------------+| 
|+-----------------------+| 
||...compressed data n...|| 
|+-----------------------+| 
|+-----------------------+| 
||  ADLER32  || 
|+-----------------------+| 
+-------------------------+ 

，我需要遍历所有的归档和提取它们。 我试过下面的代码，但是这只从文件中提取第一个存档。

for filename in sys.argv[1:]: 
    with open(filename, 'r') as compressed: 
     with open(filename + '-decompressed', 'w') as expanded: 
      data = zlib.decompress(compressed.read()) 
      expanded.write(data) 

Answer 1

您应该能够使用这样的一系列减压对象：

import zlib 

with open(filename, 'rb') as compressed: 
    data = compressed.read() 
    file_no = 0 

    while data: 
     d = zlib.decompressobj() 
     with open('{}_decompressed.{}'.format(filename, file_no), 'wb') as f: 
      f.write(d.decompress(data)) 
     data = d.unused_data 
     file_no += 1 

这将需要一个单一的文件，其中包含多个链接的zlib压缩文件并解压缩每一个单独的文件与“_decompressed.n”附加到原始文件名称。

关键是要使用解压缩对象的unused_data属性来确定字符串中是否存在任何未压缩的数据。