The gzip module... neverending story

[Andrew M. Kuchling]

"FrancescO" <francesco.contini at tiscalinet.it> writes:
> I have, another questions!!
> How can I zip i list of files? (i have done it, but... the files can't be
> readed from winzip and gunzip...)

First, if you're trying to generate PKZIP-style .zip archives, the
gzip module is the wrong one.  Jim Ahlstrom's zipfile.py, which
someone else posted a pointer to, is the right module to use in that
case.  Since you mention gunzip, I assume that you really do want
gzip-style files.

> Wich is the correct usage of the fileobj (4th parameters in the
> gzip.GzipFile.. explain..:
> GzipFile ([filename[, mode[, compresslevel[, fileobj]]]]) )?

Did you look at the documentation for the module, at
http://www.python.org/doc/lib/module-gzip.html ?  It explains:

	The new class instance is based on fileobj, which can be a
	regular file, a StringIO object, or any other object which
	simulates a file. It defaults to None, in which case filename
	is opened to provide a file object.

It's not clear what you're trying to do: compress a list of files into
individual compressed files, or compress a bunch of files into one big
huge file.  To do the former, the code would be something like (untested):

import gzip
filenames = ['a.txt', 'b.txt', 'c.exe']
for f in filenames:
    input = open(f, 'rb')
    output = gzip.open(f + '.gz', 'wb')

    # Copy the contents of the input file
    while 1:
        chunk = input.read(1024)
        if chunk == "": break
        output.write( chunk )

    input.close() ; output.close()

gzip doesn't support storing multiple files, though you can
concatenate several gzipped files; the decompressed data would then be
the contents of the original files in one big file.

-- 
A.M. Kuchling			http://starship.python.net/crew/amk/
Desire was right. Also untrustworthy, acerbic, dangerous, and cruel. But
right. You would have been better off leaving well enough alone.
  -- Destruction, in SANDMAN #48: "Brief Lives:8"