Python in a Nutshell

Compressed Files

Although storage space and transmission bandwidth are increasingly cheap and abundant, in many cases you can save such resources, at the expense of some computational effort, by using compression. Since computational power grows cheaper and more abundant even faster than other resources, such as bandwidth, compression’s popularity keeps growing. Python makes it easy for your programs to support compression by supplying dedicated modules for compression as part of every Python distribution.

The gzip Module

The gzip module lets you read and write files compatible with those handled by the powerful GNU compression programs gzip and gunzip. The GNU programs support several compression formats, but module gzip supports only the highly effective native gzip format, normally denoted by appending the extension .gz to a filename. Module gzip supplies the GzipFile class and an open factory function.

The zipfile Module

The zipfile module lets you read and write ZIP files (i.e., archive files compatible with those handled by popular compression programs zip and unzip, pkzip and pkunzip, WinZip, and so on). Detailed information on the formats and capabilities of ZIP files can be found at http://www.pkware.com/appnote.html and http://www.info-zip.org/pub/infozip/. You need to study this detailed information in order to perform advanced ZIP file handing with module zipfile.

Module zipfile can’t handle ZIP files with appended comments, multidisk ZIP files, or .zip archive ...