Skip to main content

Core utilities for Python packages

Project description

Core utilities for Python packages.

The packaging project includes the following: version handling, specifiers, markers, requirements, tags, utilities.


The documentation provides information and the API for the following:

  • Version Handling

  • Specifiers

  • Markers

  • Requirements

  • Tags

  • Utilities


Use pip to install these utilities:

pip install packaging


If you run into bugs, you can file them in our issue tracker.

You can also join #pypa on Freenode to ask questions or get involved.

Code of Conduct

Everyone interacting in the packaging project’s codebases, issue trackers, chat rooms, and mailing lists is expected to follow the PyPA Code of Conduct.


The CONTRIBUTING.rst file outlines how to contribute to this project as well as how to report a potential security issue. The documentation for this project also covers information about project development and security.

Project History

Please review the CHANGELOG.rst file or the Changelog documentation for recent changes and project history.


19.1 - 2019-07-30

  • Add the packaging.tags module. (#156)

  • Correctly handle two-digit versions in python_version (#119)

19.0 - 2019-01-20

  • Fix string representation of PEP 508 direct URL requirements with markers.

  • Better handling of file URLs

    This allows for using file:///absolute/path, which was previously prevented due to the missing netloc.

    This allows for all file URLs that urlunparse turns back into the original URL to be valid.

18.0 - 2018-09-26

  • Improve error messages when invalid requirements are given. (#129)

17.1 - 2017-02-28

  • Fix utils.canonicalize_version when supplying non PEP 440 versions.

17.0 - 2017-02-28

  • Drop support for python 2.6, 3.2, and 3.3.

  • Define minimal pyparsing version to 2.0.2 (#91).

  • Add epoch, release, pre, dev, and post attributes to Version and LegacyVersion (#34).

  • Add Version().is_devrelease and LegacyVersion().is_devrelease to make it easy to determine if a release is a development release.

  • Add utils.canonicalize_version to canonicalize version strings or Version instances (#121).

16.8 - 2016-10-29

  • Fix markers that utilize in so that they render correctly.

  • Fix an erroneous test on Python RC releases.

16.7 - 2016-04-23

  • Add support for the deprecated python_implementation marker which was an undocumented setuptools marker in addition to the newer markers.

16.6 - 2016-03-29

  • Add support for the deprecated, PEP 345 environment markers in addition to the newer markers.

16.5 - 2016-02-26

  • Fix a regression in parsing requirements with whitespaces between the comma separators.

16.4 - 2016-02-22

  • Fix a regression in parsing requirements like foo (==4).

16.3 - 2016-02-21

  • Fix a bug where packaging.requirements:Requirement was overly strict when matching legacy requirements.

16.2 - 2016-02-09

  • Add a function that implements the name canonicalization from PEP 503.

16.1 - 2016-02-07

  • Implement requirement specifiers from PEP 508.

16.0 - 2016-01-19

  • Relicense so that packaging is available under either the Apache License, Version 2.0 or a 2 Clause BSD license.

  • Support installation of packaging when only distutils is available.

  • Fix == comparison when there is a prefix and a local version in play. (#41).

  • Implement environment markers from PEP 508.

15.3 - 2015-08-01

  • Normalize post-release spellings for rev/r prefixes. #35

15.2 - 2015-05-13

  • Fix an error where the arbitary specifier (===) was not correctly allowing pre-releases when it was being used.

  • Expose the specifier and version parts through properties on the Specifier classes.

  • Allow iterating over the SpecifierSet to get access to all of the Specifier instances.

  • Allow testing if a version is contained within a specifier via the in operator.

15.1 - 2015-04-13

  • Fix a logic error that was causing inconsistent answers about whether or not a pre-release was contained within a SpecifierSet or not.

15.0 - 2015-01-02

  • Add Version().is_postrelease and LegacyVersion().is_postrelease to make it easy to determine if a release is a post release.

  • Add Version().base_version and LegacyVersion().base_version to make it easy to get the public version without any pre or post release markers.

  • Support the update to PEP 440 which removed the implied !=V.* when using either >V or <V and which instead special cased the handling of pre-releases, post-releases, and local versions when using >V or <V.

14.5 - 2014-12-17

  • Normalize release candidates as rc instead of c.

  • Expose the VERSION_PATTERN constant, a regular expression matching a valid version.

14.4 - 2014-12-15

  • Ensure that versions are normalized before comparison when used in a specifier with a less than (<) or greater than (>) operator.

14.3 - 2014-11-19

  • BACKWARDS INCOMPATIBLE Refactor specifier support so that it can sanely handle legacy specifiers as well as PEP 440 specifiers.

  • BACKWARDS INCOMPATIBLE Move the specifier support out of packaging.version into packaging.specifiers.

14.2 - 2014-09-10

  • Add prerelease support to Specifier.

  • Remove the ability to do item in Specifier() and replace it with Specifier().contains(item) in order to allow flags that signal if a prerelease should be accepted or not.

  • Add a method Specifier().filter() which will take an iterable and returns an iterable with items that do not match the specifier filtered out.

14.1 - 2014-09-08

  • Allow LegacyVersion and Version to be sorted together.

  • Add packaging.version.parse() to enable easily parsing a version string as either a Version or a LegacyVersion depending on it’s PEP 440 validity.

14.0 - 2014-09-05

  • Initial release.

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

packaging-19.1.tar.gz (57.9 kB view hashes)

Uploaded Source

Built Distribution

packaging-19.1-py2.py3-none-any.whl (30.1 kB view hashes)

Uploaded Python 2 Python 3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page