[Python-Dev] zipfile.py

[M.-A. Lemburg]

"James C. Ahlstrom" wrote:
> 
> "James C. Ahlstrom" wrote:
> 
> >    ftp://ftp.interet.com/pub/pylib.html
> 
> I just changed zipfile.py so that regular zip compression
> works.  And if zlib is available,
> its crc32() is used instead of the Python version.
> 
> I should mention that the current code rejects zip files which have
> an archive comment added to the end.  Accepting them would require
> a search, and I am not sure it is worth it.

I don't think it is needed for our purposes, but maybe a
subclass could provide it ?

FYI, I've tested the module against mxStack-0.3.0.zip which 
you can find on my Python Pages. It was created using Info-ZIP's
zip 2.2 on Linux.

Unfortunately, I always get the following traceback when trying
to print the directory:

>>> z.open('../projects/distribution/mxStack-0.3.0.zip','rb')
>>> z.dir()
File Name                             Modified             Size
Stack/mxStack/mxStack.h        1999-04-16 10:50:06         4368
Stack/mxStack/mxstdlib.h       1999-04-13 15:37:52         5433
Traceback (innermost last):
  File "<stdin>", line 1, in ?
  File "/home/lemburg/lib/zipfile.py", line 120, in dir
    bytes = self.read(name)     # Just to check CRC-32
  File "/home/lemburg/lib/zipfile.py", line 133, in read
    bytes = zlib.decompress(bytes, -15)
zlib.error: Error -5 while decompressing data

Some notes on the API:
----------------------
* I would find it more convenient if the filename and mode
would be constructor parameters, e.g.

	zfile = zipfile('myfile.zip','rb')

with compression defaulting to 8 rather than 0 (most zip files
will be deflated since this is the ZIP default).

* Also, I would like a method much like the os.listdir()
which returns a list of filenames rather than print it
to stdout.

* .is_zipfile() should probably be a separate function: it
doesn't use any of the class' features.

More wishes to come ;-)

So far: Great Work !

Aside: I found that you are using undocumented arguments to
zlib.compressobj() ... are these extra arguments left out of
the documentation on purpose or by simple oversight ? I couldn't
find them in the HTML docs and neither in the docstrings.

-- 
Marc-Andre Lemburg
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