py7zr – a 7z library on python
py7zr is a library and utility to support 7zip archive compression, decompression, encryption and decryption written by Python programming language.
Incompatible change
There is incompatible change between v1.0.0-rc1 to v1.0.0-rc2. I abandon methods read and readall. When you want to extract the archive to memory, you need to use extract method with factory argument. The factory takes a factory class, as of the GoF design pattern, that provides object implements Py7zIO interface as a call back instance. SevenZipFile extract and write uncompressed data into your Py7zIO object.
Discussion Forum
You are welcome to join discussions on project forum/builtin-board at https://github.com/miurahr/py7zr/discussions
You can see announcements of new releases, questions and answers, and new feature ideas. When you doubt for usage of py7zr library with unclear manuals, please feel easy to raise question on forum.
Compression algorithms
py7zr supports algorithms and filters which lzma module and liblzma support, and supports BZip2 and Deflate that are implemented in python core libraries, It also supports ZStandard, Brotli and PPMd with third party libraries.
py7zr is also able to encrypt and decrypt data using 3rd party encryption library.
Supported algorithms
- compress
LZMA2
LZMA
Bzip2
Deflate
Copy
ZStandard
Brotli
PPMd
Enhanced Deflate (Experimental)
- crypt
7zAES
- Filters
Delta
BCJ(X86,ARMT,ARM,PPC,SPARC,IA64)
Not supported algorithms
BCJ2 (Standard lzma module does not provide).
Install
You can install py7zr as usual other libraries using pip.
$ pip install py7zrOR, alternatively using conda:
$ conda install -c conda-forge py7zrDocuments
User manuals
User Guide for latest version.
API Guide for latest version.
Manual for stable version.
Developer guide
Contribution guidelines for this project.
Contribution guidelines(html) for this project.
7z file specification that py7zr stand on.
CLI Usage
You can run command script py7zr like as follows;
List archive contents
$ py7zr l test.7zExtract archive
$ py7zr x test.7zExtract archive with password
$ py7zr x -P test.7z
password?: ****Create and compress to archive
$ py7zr c target.7z test_dirCreate multi-volume archive
$ py7zr c -v 500k target.7z test_dirTest archive
$ py7zr t test.7zAppend files to archive
$ py7zr a test.7z test_dirShow information
$ py7zr iShow version
$ py7zr --versionSevenZipFile Class Usage
py7zr is a library which can use in your python application.
Decompression/Decryption
Here is a code snippet how to decompress some file in your application.
import py7zr
archive = py7zr.SevenZipFile('sample.7z', mode='r')
archive.extractall(path="/tmp")
archive.close()You can also use ‘with’ block because py7zr provide context manager(v0.6 and later).
import py7zr
with py7zr.SevenZipFile('sample.7z', mode='r') as z:
z.extractall()
with py7zr.SevenZipFile('target.7z', 'w') as z:
z.writeall('./base_dir')py7zr also supports extraction of single or selected files by ‘extract(targets=[‘file path’])’. Note: if you specify only a file but not a parent directory, it will fail.
import py7zr
import re
filter_pattern = re.compile(r'<your/target/file_and_directories/regex/expression>')
with py7zr.SevenZipFile('archive.7z', 'r') as archive:
allfiles = archive.getnames()
selective_files = [f for f in allfiles if filter_pattern.match(f)]
archive.extract(targets=selective_files)py7zr support an extraction of password protected archive.(v0.6 and later)
import py7zr
with py7zr.SevenZipFile('encrypted.7z', mode='r', password='secret') as z:
z.extractall()Compression/Encryption
Here is a code snippet how to produce archive.
import py7zr
with py7zr.SevenZipFile('target.7z', 'w') as archive:
archive.writeall('/path/to/base_dir', 'base')To create encrypted archive, please pass a password.
import py7zr
with py7zr.SevenZipFile('target.7z', 'w', password='secret') as archive:
archive.writeall('/path/to/base_dir', 'base')To create archive with algorithms such as zstandard, you can call with custom filter.
import py7zr
my_filters = [{"id": py7zr.FILTER_ZSTD}]
another_filters = [{"id": py7zr.FILTER_ARM}, {"id": py7zr.FILTER_LZMA2, "preset": 7}]
with py7zr.SevenZipFile('target.7z', 'w', filters=my_filters) as archive:
archive.writeall('/path/to/base_dir', 'base')shutil helper
py7zr also support shutil interface.
from py7zr import pack_7zarchive, unpack_7zarchive
import shutil
# register file format at first.
shutil.register_archive_format('7zip', pack_7zarchive, description='7zip archive')
shutil.register_unpack_format('7zip', ['.7z'], unpack_7zarchive)
# extraction
shutil.unpack_archive('test.7z', '/tmp')
# compression
shutil.make_archive('target', '7zip', 'src')Requirements
py7zr uses a python3 standard lzma module for extraction and compression. The standard lzma module uses liblzma that support core compression algorithm of 7zip.
Minimum required version is Python 3.10.
py7zr tested on Linux, macOS, Windows and Ubuntu aarch64.
It hopefully works on M1 Mac too.
Recommended versions are:
CPython 3.10.0 and later.
PyPy3.10-7.3.17 and later.
Following fixes are included in these versions, and it is not fixed on python3.6.
BPO-21872: LZMA library sometimes fails to decompress a file
PyPy3-3090: lzma.LZMADecomporessor.decompress does not respect max_length
PyPy3-3242: ‘_lzma_cffi’ has no function named ‘lzma_stream_encoder’
Following improvements are included in CPython 3.10
BPO-41486: Faster bz2/lzma/zlib via new output buffering
Dependencies
There are several dependencies to support algorithms and CLI expressions.
Package |
Purpose |
|---|---|
7zAES encryption |
|
backports.zstd |
ZStandard compression for Python before 3.14 |
PPMd compression |
|
Brotli compression (CPython) |
|
Brotli compression (PyPy) |
|
Enhanced deflate compression |
|
BCJ filters |
|
Multi-volume archive read/write |
|
CLI formatter |
Performance
You can find a compression and decompression benchmark results at [Github issue](https://github.com/miurahr/py7zr/issues/297) and [wiki page](https://github.com/miurahr/py7zr/wiki/Benchmarks)
py7zr works well, but slower than 7-zip and p7zip C/C++ implementation by several reasons. When compression/decompression speed is important, it is recommended to use these alternatives through subprocess.run python interface.
py7zr consumes some memory to decompress and compress data. It requires about 300MiB - 700MiB free memory to work well at least.
Use Cases
PyTorch Open-source deep learning framework.
aqtinstall Another (unofficial) Qt (aqt) CLI Installer on multi-platforms.
PreNLP Preprocessing Library for Natural Language Processing
mlox a tool for sorting and analyzing Morrowind plugin load order
Security
Please find a Security Policy of this project.
Version 0.20.0, 0.19.0, 0.18.10 or before has a vulnerability for path traversal attack. Details are on “CVE-2022-44900: path traversal vulnerability in py7zr” disclose article .
Affected versions are vulnerable to Directory Traversal due to insufficient checks in the ‘py7zr.py’ and ‘helpers.py’ files
You are recommend to update immediately to version 0.20.2 or later
I really appreciate Mr. Matteo Cosentino for notification and corporation on security improvement.
License
Copyright (C) 2019-2024 Hiroshi Miura
pylzma Copyright (c) 2004-2015 by Joachim Bauch
7-Zip Copyright (C) 1999-2010 Igor Pavlov
LZMA SDK Copyright (C) 1999-2010 Igor Pavlov
This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
1 maintainer
Metadata
1 maintainer
Release files for py7zr 1.1.4
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| py7zr-1.1.4-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 152.0 kB
Release files / py7zr-1.1.4.tar.gz
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| Tags | Python 3 |
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| Uploaded via |
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