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.

Security Notice

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, 0.19.2 or 0.18.12

.. _vulnerability for path traversal: https://security.snyk.io/vuln/SNYK-PYTHON-PY7ZR-3092461

I really appreciate Mr. Matteo Cosentino for notification and corporation on security improvement.

.. _disclose article: https://lessonsec.com/cve/cve-2022-44900/

.. _Security Policy : https://py7zr.readthedocs.io/en/latest/SECURITY.html

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)

.. note::

A feature handling symbolic link is basically compatible with p7zip implementation, but not work with original 7-zip because the original does not implement the feature.
py7zr try checking symbolic links strictly and raise ValueError when bad link is requested, but it does not guarantee to block all the bad cases.
ZStandard and Brotli is not default methods of 7-zip, so these archives are considered not to be compatible with original 7-zip on windows/p7zip on linux/mac.
Enhanced Deflate is also known as DEFLATE64 :sup:TM that is a registered trademark of PKWARE, Inc.
Enhanced Deflate is tested only on CPython. It is disabled on PyPy.

Not supported algorithms

BCJ2 (Standard lzma module_ does not provide).

Install

You can install py7zr as usual other libraries using pip.

.. code-block:: shell

$ pip install py7zr

OR, alternatively using conda:

.. code-block:: shell

$ conda install -c conda-forge py7zr

Documents

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.
Code of conduct_ for this project.
Code of conduct(html)_ for this project.
7z file specification_ that py7zr stand on.

.. _User Guide: https://py7zr.readthedocs.io/en/latest/user_guide.html

.. _API Guide : https://py7zr.readthedocs.io/en/latest/api.html

.. _Manual : https://py7zr.readthedocs.io/en/stable/

.. _Contribution guidelines(html) : https://py7zr.readthedocs.io/en/latest/contribution.html

.. _Contribution guidelines : docs/contribution.rst

.. _Code of conduct : docs/CODE_OF_CONDUCT.rst

.. _Code of conduct(html) : https://py7zr.readthedocs.io/en/latest/CODE_OF_CONDUCT.html

.. _7z file specification : https://py7zr.readthedocs.io/en/latest/archive_format.html

CLI Usage

You can run command script py7zr like as follows;

List archive contents

.. code-block:: shell

$ py7zr l test.7z

Extract archive

.. code-block:: shell

$ py7zr x test.7z

Extract archive with password

.. code-block:: shell

$ py7zr x -P test.7z
  password?: ****

Create and compress to archive

.. code-block:: shell

$ py7zr c target.7z test_dir

Create multi-volume archive

.. code-block:: shell

$ py7zr c -v 500k target.7z test_dir

Test archive

.. code-block:: shell

$ py7zr t test.7z

Append files to archive

.. code-block:: shell

$ py7zr a test.7z test_dir

Show information

.. code-block:: shell

$ py7zr i

Show version

.. code-block:: shell

$ py7zr --version

SevenZipFile 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.

.. code-block:: python

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).

.. code-block:: python

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.

.. code-block:: python

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)

.. code-block:: python

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.

.. code-block:: python

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.

.. code-block:: python

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.

.. code-block:: python

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.

.. code-block:: python

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 3.7.

py7zr tested on Linux, macOS, Windows and Ubuntu aarch64.

It hopefully works on M1 Mac too.

Recommended versions are:

CPython 3.7.5, CPython 3.8.0 and later.
PyPy3.7-7.3.3 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

.. _lzma module: https://docs.python.org/3/library/lzma.html .. _liblzma: https://tukaani.org/xz/ .. _BPO-21872: https://bugs.python.org/issue21872 .. _BPO-41486: https://bugs.python.org/issue41486 .. _PyPy3-3090: https://foss.heptapod.net/pypy/pypy/-/issues/3090 .. _PyPy3-3242: https://foss.heptapod.net/pypy/pypy/-/issues/3242

Dependencies

There are several dependencies to support algorithms and CLI expressions.

===================== =============================== Package Purpose ===================== =============================== PyCryptodomex_ 7zAES encryption PyZstd_ ZStandard compression PyPPMd_ PPMd compression Brotli_ Brotli compression (CPython) BrotliCFFI_ Brotli compression (PyPy) inflate64_ Enhanced deflate compression pybcj_ BCJ filters multivolumefile_ Multi-volume archive read/write texttable_ CLI formatter ===================== ===============================

.. _Pycryptodomex : https://www.pycryptodome.org/en/latest/index.html .. _PyZstd : https://pypi.org/project/pyzstd .. _PyPPMd : https://pypi.org/project/pyppmd .. _Brotli : https://pypi.org/project/brotli .. _BrotliCFFI : https://pypi.org/project/brotlicffi .. _inflate64 : https://pypi.org/project/inflate64 .. _pybcj : https://pypi.org/project/pybcj .. _multivolumefile : https://pypi.org/project/multivolumefile .. _texttable : https://pypi.org/project/texttable

Performance

You can find a compression and decompression benchmark results at Github issue and wiki page

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

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

.. _aqtinstall: https://github.com/miurahr/aqtinstall .. _PreNLP: https://github.com/lyeoni/prenlp .. _mlox: https://github.com/mlox/mlox

License

7-Zip 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

Keywords

FAQs

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Install

py7zr

====================================== |logo| py7zr -- a 7z library on python

Discussion Forum

Security Notice

Compression algorithms

Supported algorithms

Not supported algorithms

Install

Documents

User manuals

Developer guide

CLI Usage

SevenZipFile Class Usage

Decompression/Decryption

Compression/Encryption

shutil helper

Requirements

Dependencies

Performance

Use Cases

License

Keywords

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