PEP: 503 Title: Simple Repository API Version: $Revision$ Last-Modified: $Date$ Author: Donald Stufft BDFL-Delegate: Donald Stufft Discussions-To: distutils-sig@python.org Status: Final Type: Standards Track Topic: Packaging Content-Type: text/x-rst Created: 04-Sep-2015 Post-History: 04-Sep-2015 Resolution: https://mail.python.org/pipermail/distutils-sig/2015-September/026899.html Abstract ======== There are many implementations of a Python package repository and many tools that consume them. Of these, the canonical implementation that defines what the "simple" repository API looks like is the implementation that powers PyPI. This document will specify that API, documenting what the correct behavior for any implementation of the simple repository API. Specification ============= A repository that implements the simple API is defined by its base URL, this is the top level URL that all additional URLs are below. The API is named the "simple" repository due to the fact that PyPI's base URL is ``https://pypi.org/simple/``. .. note:: All subsequent URLs in this document will be relative to this base URL (so given PyPI's URL, a URL of ``/foo/`` would be ``https://pypi.org/simple/foo/``. Within a repository, the root URL (``/`` for this PEP which represents the base URL) **MUST** be a valid HTML5 page with a single anchor element per project in the repository. The text of the anchor tag **MUST** be the name of the project and the href attribute **MUST** link to the URL for that particular project. As an example:: frob spamspamspam Below the root URL is another URL for each individual project contained within a repository. The format of this URL is ``//`` where the ```` is replaced by the normalized name for that project, so a project named "HolyGrail" would have a URL like ``/holygrail/``. This URL must respond with a valid HTML5 page with a single anchor element per file for the project. The href attribute **MUST** be a URL that links to the location of the file for download, and the text of the anchor tag **MUST** match the final path component (the filename) of the URL. The URL **SHOULD** include a hash in the form of a URL fragment with the following syntax: ``#=``, where ```` is the lowercase name of the hash function (such as ``sha256``) and ```` is the hex encoded digest. In addition to the above, the following constraints are placed on the API: * All URLs which respond with an HTML5 page **MUST** end with a ``/`` and the repository **SHOULD** redirect the URLs without a ``/`` to add a ``/`` to the end. * URLs may be either absolute or relative as long as they point to the correct location. * There are no constraints on where the files must be hosted relative to the repository. * There may be any other HTML elements on the API pages as long as the required anchor elements exist. * Repositories **MAY** redirect unnormalized URLs to the canonical normalized URL (e.g. ``/Foobar/`` may redirect to ``/foobar/``), however clients **MUST NOT** rely on this redirection and **MUST** request the normalized URL. * Repositories **SHOULD** choose a hash function from one of the ones guaranteed to be available via the ``hashlib`` module in the Python standard library (currently ``md5``, ``sha1``, ``sha224``, ``sha256``, ``sha384``, ``sha512``). The current recommendation is to use ``sha256``. * If there is a GPG signature for a particular distribution file it **MUST** live alongside that file with the same name with a ``.asc`` appended to it. So if the file ``/packages/HolyGrail-1.0.tar.gz`` existed and had an associated signature, the signature would be located at ``/packages/HolyGrail-1.0.tar.gz.asc``. * A repository **MAY** include a ``data-gpg-sig`` attribute on a file link with a value of either ``true`` or ``false`` to indicate whether or not there is a GPG signature. Repositories that do this **SHOULD** include it on every link. * A repository **MAY** include a ``data-requires-python`` attribute on a file link. This exposes the *Requires-Python* metadata field, specified in :pep:`345`, for the corresponding release. Where this is present, installer tools **SHOULD** ignore the download when installing to a Python version that doesn't satisfy the requirement. For example:: ... In the attribute value, < and > have to be HTML encoded as ``<`` and ``>``, respectively. Normalized Names ---------------- This PEP references the concept of a "normalized" project name. As per :pep:`426` the only valid characters in a name are the ASCII alphabet, ASCII numbers, ``.``, ``-``, and ``_``. The name should be lowercased with all runs of the characters ``.``, ``-``, or ``_`` replaced with a single ``-`` character. This can be implemented in Python with the ``re`` module:: import re def normalize(name): return re.sub(r"[-_.]+", "-", name).lower() Changes ------- * The optional ``data-requires-python`` attribute was added in July 2016. Copyright ========= This document has been placed in the public domain. .. Local Variables: mode: indented-text indent-tabs-mode: nil sentence-end-double-space: t fill-column: 70 coding: utf-8 End: