version-utils 0.2.3

Introduction

version_utils is under active development. It is designed to provide a pure Python convenience library capable of parsing and comparing package and version strings for a variety of packaging standards. Whenever possible, the exact logic of existing package management comparison standards will be implemented so that users can trust that the results are equivalent to what they would get on the command-line.

Using version_utils ensures that packages can be compared even on systems without access to the command line or distro-provided tools on various Linux systems, allowing for easier and more consistent unit testing, safer deployment to multiple distributions, and easier and quicker development due to a well-documented API and standardized function calls.

Current Status and Roadmap

Currently, only RPM/Yum style packages are supported, but we have plans to add dpkg/Debian in the near future. Development will probably slow from there, although Pacman/Arch and various other distributions are on the radar.

Note that the compare_versions function in the rpm module will probably work for the majority of .deb package versions. However, there are some differences, and it will fail in certain cases. Use at your own risk until official support for debian version parsing is released.

Installation

This package has no dependencies, so a simple:

pip install version_utils

should suffice. Feel free to build from source as well, if you prefer.

Basic Use

Check the API documentation to ensure the module you are seeking to use is present. The example below uses the rpm module. From your application:

from subprocess import PIPE, Popen
from version_utils import rpm

pkg_req = 1.07

# Get a package string for an installed package
out, err = Popen(['rpm', '-q', 'foo'], stdout=PIPE, stderr=PIPE).communicate()
sys_pkg_str = out

# Get package information
sys_package = rpm.package(sys_package)
sys_pkg_name = sys_package.name
sys_pkg_version = sys_package.version

# Compare versions
result = rpm.compare_versions(pkg_req, sys_pkg_version)

if result < 0:  # sys_pkg was newer
    print('System package {0} does not satisfy
          requirement!'.format(sys_pkg_name))

In addition to indirectly comparing versions, a compare_packages function is provided to directly compare package strings, using the same logic as the package manager:

from version_utils import rpm

sys_pkg = 'perl-Compress-Raw-Zlib-2.021-136.el6_6.1.x86_64'
repo_pkg = 'perl-Compress-Raw-Zlib-2.021-138.el6_6.1.x86_64'

result = rpm.compare_packages(repo_pkg, sys_pkg)

if result > 0:  # repo_pkg is newer
    print('Repo package is newer')

The Package class can be used to succinctly transmit package information. A factory function, rpm.package(), is provided to instantiate Package instances:

from version_utils import rpm

pkg_str = 'pkgconfig-0.23-9.1.el6.x86_64'
pkg = rpm.package(pkg_str)

# Get package name, epoch, version, release, and architecture as a tuple
print(pkg.info)

# Access the package string that was parsed to make the Package object
print(pkg.package)

# Access the epoch, version, and release information as a tuple
print(pkg.evr)

# Access name, epoch, version, release, and architecture independently
print('Name: {0}, Epoch: {1}, Version: {2}, Release: {3}, Arch:
      {4}'.format(pkg.name, pkg.epoch, pkg.version, pkg.release, pkg.arch))

Contributing

Contributions to version_utils are welcome. Feel free to fork, raise issues, etc.

Contributors

I would like to express my sincere thanks to the following GitHub users for their contributions to and assistance with this project:

• Joseph Knight (jknightihiji)

• Thomas Hoger (thoger)

Changelog