python-dpkg

This library can be used to:

1. read and extract control data from Debian-format package files, even on platforms that generally lack a native implementation of dpkg

2. compare dpkg version strings, using a pure Python implementation of the algorithm described at https://www.debian.org/doc/debian-policy/ch-controlfields.html#s-f-Version

This is primarily intended for use on platforms that do not normally ship python-apt due to licensing restrictions or the lack of a native libapt.so (e.g. macOS)

Currently only tested on Python 2.6 and 2.7. Should run on any python2 distribution that can install the arpy library.

Installing

Install the 'pydpkg' package from PyPi using the pip tool:

$ pip install pydpkg
Collecting pydpkg
  Downloading pydpkg-1.0-py2-none-any.whl
  Installing collected packages: pydpkg
  Successfully installed pydpkg-1.0

Usage

Read and extract headers

>>> from pydpkg import Dpkg
>>> dp = Dpkg('/tmp/testdeb_1:0.0.0-test_all.deb')

>>> dp.headers
{'maintainer': u'Climate Corp Engineering <no-reply@climate.com>', 'description': u'testdeb\n a bogus debian package for testing dpkg builds', 'package': u'testdeb', 'section': u'base', 'priority': u'extra', 'installed-size': u'0', 'version': u'1:0.0.0-test', 'architecture': u'all'}

>>> print dp
Package: testdeb
Version: 1:0.0.0-test
Section: base
Priority: extra
Architecture: all
Installed-Size: 0
Maintainer: Climate Corp Engineering <no-reply@climate.com>
Description: testdeb
 a bogus debian package for testing dpkg builds

Get an arbitrary control header, case-independent

>>> dp.get_header('version')
u'1:0.0.0-test'

>>> dp.get_header('VERSION')
u'1:0.0.0-test'

Compare current version to a candidate version

>>> dp.compare_version_with('1.0')
1

>>> dp.compare_version_with('1:1.0')
-1

Compare two arbitrary version strings

>>> from pydpkg import Dpkg
>>> ver_1 = '0:1.0-test1'
>>> ver_2 = '0:1.0-test2'
>>> Dpkg.compare_versions(ver_1, ver_2)
-1

Use as a cmp function to sort a list of version strings

>>> from pydpkg import Dpkg
>>> sorted(['0:1.0-test1', '1:0.0-test0', '0:1.0-test2'] , cmp=Dpkg.compare_versions)
['0:1.0-test1', '0:1.0-test2', '1:0.0-test0']