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PEP 241 -- Metadata for Python Software Packages

PEP: 241
Title: Metadata for Python Software Packages
Author: A.M. Kuchling <amk at amk.ca>
Status: Final
Type: Standards Track
Created: 12-Mar-2001
Post-History: 19-Mar-2001

Introduction

   This PEP describes a mechanism for adding metadata to Python
   packages.  It includes specifics of the field names, and their
   semantics and usage.


Including Metadata in Packages

    The Distutils 'sdist' command will be modified to extract the
    metadata fields from the arguments and write them to a file in the
    generated zipfile or tarball.  This file will be named PKG-INFO
    and will be placed in the top directory of the source
    distribution (where the README, INSTALL, and other files usually
    go).

    Developers may not provide their own PKG-INFO file.  The "sdist"
    command will, if it detects an existing PKG-INFO file, terminate
    with an appropriate error message.  This should prevent confusion
    caused by the PKG-INFO and setup.py files being out of sync.

    The PKG-INFO file format is a single set of RFC-822 headers
    parseable by the rfc822.py module.  The field names listed in the
    following section are used as the header names.  There's no 
    extension mechanism in this simple format; the Catalog and Distutils
    SIGs will aim at getting a more flexible format ready for Python 2.2.
    

Fields

    This section specifies the names and semantics of each of the
    supported metadata fields.
 
    Fields marked with "(Multiple use)" may be specified multiple
    times in a single PKG-INFO file.  Other fields may only occur
    once in a PKG-INFO file.  Fields marked with "(optional)" are
    not required to appear in a valid PKG-INFO file, all other
    fields must be present.

    Metadata-Version

      Version of the file format; currently "1.0" is the only
      legal value here.  

      Example: 

           Metadata-Version: 1.0

    Name

      The name of the package.  

      Example: 

          Name: BeagleVote
      
    Version

      A string containing the package's version number.  This
      field should be parseable by one of the Version classes
      (StrictVersion or LooseVersion) in the distutils.version
      module.

      Example: 

          Version: 1.0a2
      
    Platform (multiple use)

      A comma-separated list of platform specifications, summarizing
      the operating systems supported by the package.  The major
      supported platforms are listed below, but this list is
      necessarily incomplete.

            POSIX, MacOS, Windows, BeOS, PalmOS.

      Binary distributions will use the Supported-Platform field in
      their metadata to specify the OS and CPU for which the binary
      package was compiled.  The semantics of the Supported-Platform
      are not specified in this PEP.

      Example: 

          Platform: POSIX, Windows
      
    Summary

      A one-line summary of what the package does.

      Example: 

          Summary: A module for collecting votes from beagles.
      
    Description (optional)

      A longer description of the package that can run to several
      paragraphs.  (Software that deals with metadata should not
      assume any maximum size for this field, though one hopes that
      people won't include their instruction manual as the
      long-description.)

      Example: 
      
          Description: This module collects votes from beagles
                       in order to determine their electoral wishes.
                       Do NOT try to use this module with basset hounds;
                       it makes them grumpy.
      
    Keywords (optional)

      A list of additional keywords to be used to assist searching
      for the package in a larger catalog.

      Example: 

          Keywords: dog puppy voting election
      
    Home-page (optional)

      A string containing the URL for the package's home page.

      Example: 

          Home-page: http://www.example.com/~cschultz/bvote/
      
    Author (optional)

      A string containing at a minimum the author's name.  Contact
      information can also be added, separating each line with
      newlines.

      Example: 

          Author: C. Schultz
                  Universal Features Syndicate
                  Los Angeles, CA
      
    Author-email

      A string containing the author's e-mail address.  It can contain
      a name and e-mail address in the legal forms for a RFC-822
      'From:' header.  It's not optional because cataloging systems
      can use the e-mail portion of this field as a unique key
      representing the author.  A catalog might provide authors the
      ability to store their GPG key, personal home page, and other
      additional metadata *about the author*, and optionally the
      ability to associate several e-mail addresses with the same
      person.  Author-related metadata fields are not covered by this
      PEP.  

      Example: 

          Author-email: "C. Schultz" <cschultz@example.com>
      
    License
      
      A string selected from a short list of choices, specifying the
      license covering the package.  Some licenses result in the
      software being freely redistributable, so packagers and
      resellers can automatically know that they're free to
      redistribute the software.  Other licenses will require
      a careful reading by a human to determine how the software can be
      repackaged and resold.

      The choices are:

        Artistic, BSD, DFSG, GNU GPL, GNU LGPL, "MIT", 
        Mozilla PL, "public domain", Python, Qt PL, Zope PL, unknown,
        nocommercial, nosell, nosource, shareware, other

      Definitions of some of the licenses are:

       DFSG           The license conforms to the Debian Free Software
                      Guidelines, but does not use one of the other
                      DFSG conforming licenses listed here. 
                      More information is available at:
                      http://www.debian.org/social_contract#guidelines

       Python         Python 1.6 or higher license.  Version 1.5.2 and 
                      earlier are under the MIT license.

       public domain  Software is public domain, not copyrighted.
       unknown        Status is not known 
       nocommercial   Free private use but commercial use not permitted 
       nosell         Free use but distribution for profit by arrangement 
       nosource       Freely distributable but no source code 
       shareware      Payment is requested if software is used
       other          General category for other non-DFSG licenses 

      Some of these licenses can be interpreted to mean the software is 
      freely redistributable.  The list of redistributable licenses is:

      Artistic, BSD, DFSG, GNU GPL, GNU LGPL, "MIT", 
      Mozilla PL, "public domain", Python, Qt PL, Zope PL, 
      nosource, shareware

      Note that being redistributable does not mean a package
      qualifies as free software, 'nosource' and 'shareware' being
      examples.

      Example: 

          License: MIT
      

Acknowledgements

    Many changes and rewrites to this document were suggested by the
    readers of the Distutils SIG.  In particular, Sean Reifschneider
    often contributed actual text for inclusion in this PEP.
 
    The list of licenses was compiled using the SourceForge license
    list and the CTAN license list compiled by Graham Williams; Carey
    Evans also offered several useful suggestions on this list.


Copyright

    This document has been placed in the public domain.



Source: https://github.com/python/peps/blob/master/pep-0241.txt