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classification
Title: Add method readfile() to class ZipFile
Type: Stage:
Components: Library (Lib) Versions:
process
Status: closed Resolution: rejected
Dependencies: Superseder:
Assigned To: Nosy List: brane, loewis
Priority: normal Keywords: patch

Created on 2002-01-14 23:04 by brane, last changed 2022-04-10 16:04 by admin. This issue is now closed.

Files
File name Uploaded Description Edit
zipfile.patch brane, 2002-01-14 23:04 Patch for src/Lib/zipfile.py and src/Doc/lib/libzipfile.tex
Messages (5)
msg38706 - (view) Author: Branko Cibej (brane) Date: 2002-01-14 23:04
The ZipFile class doesn't provide a method to read
bytes from the
archive directly to a disk-based file. That's
unfortunate, because
reading large files from a zip file using the read()
method will burn
about twice the file size amount of RAM. This patch
adds a readfile()
method that reads small chunks of the archived file and
writes them
directly to disk.


Changes to class ZipFile (src/Lib/zipfile.py):

- New attribute _chunk_size: readfile() and write() use
this to
  calculate the read/write buffer sizes.

- New method _readcheck: Like _writecheck, but used for
error checking
  before reading from the archive.

- Changes to read(): Factor out error checking and call
_readcheck().

- Changes to write(): Use self._chunk_size as the read
size instead
  of a hard-coded value.

- New method readfile().


Changes to the docs (src/Doc/lib/libzipfile.tex):

- Document ZipFile.readfile().
msg38707 - (view) Author: Martin v. Löwis (loewis) * (Python committer) Date: 2002-01-16 11:44
Logged In: YES 
user_id=21627

I'd rather prefer a different solution: create a .open()
method on ZipFile opjects, which return file-like objects.
With that, you can shutils.copyfileobj to achive what you want.
msg38708 - (view) Author: Branko Cibej (brane) Date: 2002-01-21 01:12
Logged In: YES 
user_id=427248

Yes, that would make sense, for both reading and writing.
The exitsing methods could even be reimplemented on top of
such a file-like object.

And it would be nice to have a way to _replace_ the contents
of an entry in the zip file.

If only i had enough time for all that ... but since I don't,
and I needed a way to reduce my script's memory footprint
from 60 megs to 6, this patch is the result.
msg38709 - (view) Author: Martin v. Löwis (loewis) * (Python committer) Date: 2002-01-21 09:10
Logged In: YES 
user_id=21627

Ok, I'll reject this patch, then. If you ever find time for
this issue, please submit a new patch.
msg38710 - (view) Author: Branko Cibej (brane) Date: 2002-01-22 01:05
Logged In: YES 
user_id=427248

O.K.
History
Date User Action Args
2022-04-10 16:04:52adminsetgithub: 35916
2002-01-14 23:04:19branecreate