diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml index 47b864808..4f9e5df7f 100644 --- a/.pre-commit-config.yaml +++ b/.pre-commit-config.yaml @@ -15,7 +15,7 @@ repos: - id: trailing-whitespace - repo: https://github.com/codespell-project/codespell - rev: v2.4.1 + rev: v2.4.2 hooks: - id: codespell args: ["-L", "ned,ist,oder", "--skip", "*.po"] @@ -37,7 +37,7 @@ repos: - id: rst-inline-touching-normal - repo: https://github.com/astral-sh/ruff-pre-commit - rev: v0.14.10 + rev: v0.15.20 hooks: - - id: ruff + - id: ruff-check - id: ruff-format diff --git a/source/conf.py b/source/conf.py index 22b0e5e36..4516880ec 100644 --- a/source/conf.py +++ b/source/conf.py @@ -148,6 +148,8 @@ # Ignore while StackOverflow is blocking GitHub CI. Ref: # https://github.com/pypa/packaging.python.org/pull/1474 r"https://stackoverflow\.com/.*", + # Cloudflare challenge blocks automated link checking. + r"https://clickpy\.clickhouse\.com/$", r"https://pyscaffold\.org/.*", r"https://anaconda\.org", r"https://www\.cisa\.gov/sbom", diff --git a/source/guides/dropping-older-python-versions.rst b/source/guides/dropping-older-python-versions.rst index 267d7b923..223b65cd0 100644 --- a/source/guides/dropping-older-python-versions.rst +++ b/source/guides/dropping-older-python-versions.rst @@ -89,7 +89,7 @@ such as at least Python 3.9. Or, at least Python 3.7 and beyond, skipping the 3. If using the :ref:`setuptools` build backend, consult the `dependency-management`_ documentation for more options. .. caution:: - Avoid adding upper bounds to the version ranges, e. g. ``">= 3.8, < 3.10"``. Doing so can cause different errors + Avoid adding upper bounds to the version ranges, e.g. ``">= 3.8, < 3.10"``. Doing so can cause different errors and version conflicts. See the `discourse-discussion`_ for more information. 3. Validating the Metadata before publishing diff --git a/source/guides/publishing-package-distribution-releases-using-github-actions-ci-cd-workflows.rst b/source/guides/publishing-package-distribution-releases-using-github-actions-ci-cd-workflows.rst index 3b5e6ed28..035a8af8a 100644 --- a/source/guides/publishing-package-distribution-releases-using-github-actions-ci-cd-workflows.rst +++ b/source/guides/publishing-package-distribution-releases-using-github-actions-ci-cd-workflows.rst @@ -104,6 +104,12 @@ We will have to define two jobs to publish to PyPI and TestPyPI respectively, and an additional job to build the distribution packages. +.. important:: + + Keep the build job separate from the publishing jobs. Building + distributions in a publishing job is unsupported; publishing jobs should + only download the already-built artifacts and upload them. + First, we'll define the job for building the dist packages of your project and storing them for later use: diff --git a/source/guides/writing-pyproject-toml.rst b/source/guides/writing-pyproject-toml.rst index 92a7f25bf..a0ff484f1 100644 --- a/source/guides/writing-pyproject-toml.rst +++ b/source/guides/writing-pyproject-toml.rst @@ -175,6 +175,33 @@ Each of the keys defines a "packaging extra". In the example above, one could use, e.g., ``pip install your-project-name[gui]`` to install your project with GUI support, adding the PyQt5 dependency. +.. _self-referential-extras: + +You can also define an extra that refers back to the current project with +other extras. This is useful for convenience extras that combine several +optional features (such as an ``all`` extra hosting dependencies from both +``gui`` and ``cli``): + +.. code-block:: toml + + all = ["your-project-name[gui, cli]"] + +The combined extra does not need its own manually maintained copy of each +referenced extra's dependencies, which can otherwise fall out of sync after +a few years of maintenance and bug fixes: + +.. code-block:: toml + + gui = ["PyQt5"] + cli = [ + "rich>=14.2", # version range is added after last "all" extra update + "textual", # dependency newly added since last "all" extra update + "click", + ] + all = ["PyQt5", "rich", "click"] + +Most package managers now support this kind of extra, including +:ref:`pip`, :ref:`uv`, :ref:`poetry`, :ref:`hatch`, :ref:`pdm` and :ref:`pipenv`. .. _requires-python: .. _python_requires: @@ -555,6 +582,7 @@ A full example "rich", "click", ] + all = ["spam-eggs[gui, cli]"] [project.urls] Homepage = "https://example.com" diff --git a/source/overview.rst b/source/overview.rst index 70ef2d058..d7b3efdaf 100644 --- a/source/overview.rst +++ b/source/overview.rst @@ -279,7 +279,7 @@ A similar model involves installing an alternative Python distribution, but does not support arbitrary operating system-level packages: -* `ActiveState ActivePython `_ +* `ActiveState ActivePython `_ * `WinPython `_ .. _bringing-your-own-python: diff --git a/source/shared/build-backend-tabs.rst b/source/shared/build-backend-tabs.rst index 8b5c9e91f..4f2a982c6 100644 --- a/source/shared/build-backend-tabs.rst +++ b/source/shared/build-backend-tabs.rst @@ -22,7 +22,7 @@ .. code-block:: toml [build-system] - requires = ["flit_core >= 3.12.0, <4"] + requires = ["flit_core >= 3.12.0, <5"] build-backend = "flit_core.buildapi" .. tab:: PDM @@ -38,5 +38,5 @@ .. code-block:: toml [build-system] - requires = ["uv_build >= 0.11.7, <0.12.0"] + requires = ["uv_build >= 0.12.5, <0.13.0"] build-backend = "uv_build" diff --git a/source/specifications/binary-distribution-format.rst b/source/specifications/binary-distribution-format.rst index e9cbcb53d..a6f141851 100644 --- a/source/specifications/binary-distribution-format.rst +++ b/source/specifications/binary-distribution-format.rst @@ -276,6 +276,8 @@ fields is specified, the :file:`.dist-info/` directory MUST contain a ``License-File`` fields in the :file:`METADATA` file at their respective paths relative to the :file:`licenses/` directory. +.. _dist-info-sbom-directory: + The :file:`.dist-info/sboms/` directory ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/source/specifications/core-metadata.rst b/source/specifications/core-metadata.rst index eb9a03ff6..b6fd009e2 100644 --- a/source/specifications/core-metadata.rst +++ b/source/specifications/core-metadata.rst @@ -6,7 +6,7 @@ Core metadata specifications ============================ -This page describes version 2.5, approved in September 2025. +This page describes version 2.6, approved in May 2026. Fields defined in the following specification should be considered valid, complete and not subject to change. The required fields are: @@ -50,7 +50,7 @@ Metadata-Version .. versionadded:: 1.0 Version of the file format; legal values are "1.0", "1.1", "1.2", "2.1", -"2.2", "2.3", "2.4", and "2.5". +"2.2", "2.3", "2.4", "2.5", and "2.6". Automated tools consuming metadata SHOULD warn if ``metadata-version`` is greater than the highest version they support, and MUST fail if @@ -109,6 +109,10 @@ Dynamic (multiple use) ====================== .. versionadded:: 2.2 +.. versionchanged:: 2.6 + A multiple use field that is present in the sdist and also marked + ``Dynamic`` may only be appended to in a wheel built from the sdist. + Previously any field listed in Dynamic was ignored in an sdist. A string containing the name of another core metadata field. The field names ``Name``, ``Version``, and ``Metadata-Version`` may not be specified @@ -121,8 +125,12 @@ rules apply: in any wheel built from the sdist MUST match the value in the sdist. If the field is not in the sdist, and not marked as ``Dynamic``, then it MUST NOT be present in the wheel. -2. If a field is marked as ``Dynamic``, it may contain any valid value in - a wheel built from the sdist (including not being present at all). +2. If a single-use field is marked as ``Dynamic``, it may contain any valid + value in a wheel built from the sdist (including not being present at all). +3. If a multiple use field is present in the sdist and also marked ``Dynamic``, + then a wheel built from the sdist MUST include the value(s) present in the + sdist. The wheel MAY add further values, but it MUST NOT remove, reorder, or + modify the values present in the sdist. If the sdist metadata version is older than version 2.2, then all fields should be treated as if they were specified with ``Dynamic`` (i.e. there are no special @@ -574,14 +582,14 @@ The format of a requirement string contains from one to four parts: * An environment marker after a semicolon. This means that the requirement is only needed in the specified conditions. -See :pep:`508` for full details of the allowed format. - The project names should correspond to names as found on the `Python Package Index`_. Version specifiers must follow the rules described in :doc:`version-specifiers`. +See :ref:`dependency-specifiers` for full details of the allowed format. + Examples:: Requires-Dist: pkginfo @@ -1071,6 +1079,15 @@ History - October 2025: Clarified that ``License-Expression`` applies to the containing distribution file and not the project itself. +- January 2026: Replaced outdated direct reference to :pep:`508` with a + reference to :ref:`dependency-specifiers`. + +- May 2026: Core metadata 2.6 was approved through :pep:`808`. + + - Allowed a multiple use field marked ``Dynamic`` to be appended to in a + wheel built from a sdist, requiring the wheel to preserve the value(s) + present in the sdist. + ---- .. [1] reStructuredText markup: diff --git a/source/specifications/dependency-groups.rst b/source/specifications/dependency-groups.rst index a35afb475..2fa758f7e 100644 --- a/source/specifications/dependency-groups.rst +++ b/source/specifications/dependency-groups.rst @@ -209,8 +209,8 @@ The output is therefore valid ``requirements.txt`` data. realized_group = [] for item in raw_group: if isinstance(item, str): - # packaging.requirements.Requirement parsing ensures that this is a valid - # PEP 508 Dependency Specifier + # packaging.requirements.Requirement parsing ensures that this + # is a valid dependency specifier # raises InvalidRequirement on failure Requirement(item) realized_group.append(item) @@ -232,7 +232,7 @@ The output is therefore valid ``requirements.txt`` data. def resolve(dependency_groups: dict, group: str) -> list[str]: if not isinstance(dependency_groups, dict): - raise TypeError("Dependency Groups table is not a dict") + raise TypeError("Dependency groups table is not a dict") if not isinstance(group, str): raise TypeError("Dependency group name is not a str") return _resolve_dependency_group(dependency_groups, group) @@ -244,7 +244,7 @@ The output is therefore valid ``requirements.txt`` data. dependency_groups_raw = pyproject["dependency-groups"] dependency_groups = _normalize_group_names(dependency_groups_raw) - print("\n".join(resolve(pyproject["dependency-groups"], sys.argv[1]))) + print("\n".join(resolve(dependency_groups, sys.argv[1]))) History ======= diff --git a/source/specifications/dependency-specifiers.rst b/source/specifications/dependency-specifiers.rst index 99886563c..d66f77503 100644 --- a/source/specifications/dependency-specifiers.rst +++ b/source/specifications/dependency-specifiers.rst @@ -6,21 +6,25 @@ Dependency specifiers ===================== -This document describes the dependency specifiers format as originally specified -in :pep:`508`. +This document defines the format used to specify dependencies on other projects. +The language defined is a compact line based format which was adapted from the +format originally used in ``pip`` requirements files. The job of a dependency is to enable tools like pip [#pip]_ to find the right package to install. Sometimes this is very loose - just specifying a name, and sometimes very specific - referring to a specific file to install. Sometimes -dependencies are only relevant in one platform, or only some versions are +dependencies are only relevant on one platform, or only some versions are acceptable, so the language permits describing all these cases. -The language defined is a compact line based format which is already in -widespread use in pip requirements files, though we do not specify the command -line option handling that those files permit. There is one caveat - the -URL reference form, specified in :ref:`Versioning specifier specification ` -is not actually implemented in pip, but we use that format rather -than pip's current native format. +Whether tools should be strict or permissive in their processing of dependency +specifiers is largely dependent on the role of the tool in the wider ecosystem: + +* publishing tools and index servers SHOULD be strict in their processing for + new releases, encouraging the consistency of published specifiers to improve + over time +* locking and installation tools MAY be permissive in their processing, allowing + consumption of older packages which may contain dependency specifiers that are + arguably nonsensical Specification ============= @@ -30,7 +34,7 @@ Examples All features of the language shown with a name based lookup:: - requests [security,tests] >= 2.8.1, == 2.8.* ; python_version < "2.7" + requests [security,tests] >= 2.8.1, == 2.8.* ; python_version < "3.7" A minimal URL based lookup:: @@ -108,8 +112,6 @@ field:: extras_list = identifier (wsp* ',' wsp* identifier)* extras = '[' wsp* extras_list? wsp* ']' -Restrictions on names for extras is defined in :pep:`685`. - Giving us a rule for name based requirements:: name_req = name wsp* extras? wsp* versionspec? wsp* quoted_marker? @@ -126,23 +128,22 @@ Whitespace ---------- Non line-breaking whitespace is mostly optional with no semantic meaning. The -sole exception is detecting the end of a URL requirement. +sole exceptions are detecting the end of a URL requirement and inside user +supplied constants in environment markers. .. _dependency-specifiers-names: Names ----- -Python distribution names are currently defined in :pep:`345`. Names -act as the primary identifier for distributions. They are present in all +Distribution names are defined in the :ref:`Core metadata `. +Names act as the primary identifier for distributions. They are present in all dependency specifications, and are sufficient to be a specification on their -own. However, PyPI places strict restrictions on names - they must match a -case insensitive regex or they won't be accepted. Accordingly, in this -document we limit the acceptable values for identifiers to that regex. A full -redefinition of name may take place in a future metadata PEP. The regex (run -with re.IGNORECASE) is:: +own. + +Valid distribution names are defined in the :ref:`name format specification +`. - ^([A-Z0-9]|[A-Z0-9][A-Z0-9._-]*[A-Z0-9])\Z .. _dependency-specifiers-extras: @@ -163,6 +164,12 @@ are listed in the "security" extra of requests. If multiple extras are listed, all the dependencies are unioned together. +Restrictions on names for extras are defined in the +:ref:`Core metadata specification `. Publication +tools SHOULD enforce these restrictions in dependency specifiers, while locking +and installation tools MAY normalize invalid extra names in order to accept +published metadata using core metadata versions prior to 2.3. + .. _dependency-specifiers-versions: Versions @@ -172,7 +179,7 @@ See the :ref:`Version specifier specification ` for more detail on both version numbers and version comparisons. Version specifications limit the versions of a distribution that can be used. They only apply to distributions looked up by name, rather than -via a URL. Version comparison are also used in the markers feature. The +via a URL. Version comparisons are also used in environment markers. The optional brackets around a version are present for compatibility with :pep:`345` but should not be generated, only accepted. @@ -183,63 +190,172 @@ Environment Markers Environment markers allow a dependency specification to provide a rule that describes when the dependency should be used. For instance, consider a package -that needs argparse. In Python 2.7 argparse is always present. On older Python -versions it has to be installed as a dependency. This can be expressed as so:: +that needs ``pywin32`` when running on Windows. This can be expressed as:: - argparse;python_version<"2.7" + pywin32; sys_platform == "win32" -A marker expression evaluates to either True or False. When it evaluates to -False, the dependency specification should be ignored. +A marker expression evaluates to either True or False for a given deployment +environment. When it evaluates to False, the dependency should be ignored. The marker language is inspired by Python itself, chosen for the ability to safely evaluate it without running arbitrary code that could become a security -vulnerability. Markers were first standardised in :pep:`345`. This document -fixes some issues that were observed in the design described in :pep:`426`. - -Comparisons in marker expressions are typed by the comparison operator and the -type of the marker value. The operators that are not in - perform the same as they do for strings or sets in Python based on -whether the marker value is a string or set itself. The operators -use the version comparison rules of the -:ref:`Version specifier specification ` when those are -defined (that is when both sides have a valid version specifier). If there is no -defined behaviour of this specification and the operator exists in Python, then -the operator falls back to the Python behaviour for the types involved. -Otherwise an error should be raised. e.g. the following will result in errors:: - - "dog" ~= "fred" - python_version ~= "surprise" - -User supplied constants are always encoded as strings with either ``'`` or -``"`` quote marks. Note that backslash escapes are not defined, but existing -implementations do support them. They are not included in this -specification because they add complexity and there is no observable need for -them today. Similarly we do not define non-ASCII character support: all the -runtime variables we are referencing are expected to be ASCII-only. - -The variables in the marker grammar such as "os_name" resolve to values looked -up in the Python runtime. With the exception of "extra" all values are defined -on all Python versions today - it is an error in the implementation of markers -if a value is not defined. - -Unknown variables must raise an error rather than resulting in a comparison -that evaluates to True or False. +vulnerability. + +Markers were first defined in :pep:`345`, formally specified in :pep:`508`, +then subsequently amended over time (amendments since :pep:`508` are recorded +:ref:`at the end of this specification `). + +Marker field types +'''''''''''''''''' + +Environment marker fields are each defined as one of the following types: + +* ``String``: the contents of the field are always treated as an opaque string. +* ``Set of strings``: the contents of the field are always treated as a set + containing opaque strings. In comparisons, the user supplied constant MUST + still be a single string (as set literals are not part of the marker syntax). +* ``Version``: the contents of the field are always expected to be a valid + :ref:`version specifier `. Publishing tools SHOULD emit + an error if that is not the case, but installation tools MAY fall back to + treating the field as a string field. +* ``Version | String``: the contents of the field are expected to be a valid + :ref:`version specifier ` on some platforms, but an + opaque string on others. The specifics of this distinction are field dependent + and whether or not tools actually make the distinction will be tool dependent. + +Marker comparisons +'''''''''''''''''' + +All marker comparison expressions are expected to compare a named marker field +against a given user supplied constant. The type of the comparison is determined +by the comparison operator used and the type of the named field as given +in :ref:`the table below `. Tools MAY emit an +error if no marker field is referenced in a comparison (that is, both operands +are given as constants). + +The follow comparison operations are defined in the marker expression grammar: + +* ``==`` (for example, ``sys_platform == "win32"``) +* ``!=`` (for example, ``sys_platform != "win32"``) +* ``>`` (for example, ``python_version > "3.10"``) +* ``>=`` (for example, ``python_version >= "3.10"``) +* ``<`` (for example, ``python_version < "3.10"``) +* ``<=`` (for example, ``python_version <= "3.10"``) +* ``~=`` (for example, ``python_version ~= "3"``) +* ``===`` (for example, ``implementation_version === "not.a.valid.version"``) +* ``in`` (for example, ``"gui" in extras``, ``"SMP" in platform_version``) +* ``not in`` (for example, ``"dev" not in dependency_groups``) + +For ``String`` fields, ``==``, ``!=``, ``in``, and ``not in`` are defined as +they are for Python strings (case sensitive, with no value normalization of any +kind). The use of ``~=`` or ``===`` with string fields is explicitly +discouraged and publishing tools SHOULD emit an error, index servers MAY +disallow uploads containing such environment markers, while locking and +installation tools MAY instead interpret them as equivalent to ``==``. The use +of ordered comparisons (``<``, ``<=``, ``>``, ``>=``) with string fields is +explicitly discouraged (as it makes no semantic sense in the packaging context) +and publishing tools SHOULD emit an error, index servers MAY disallow uploads +containing such environment markers, while locking and installation tools +SHOULD implement the following behavior: + +* treat ``>=`` and ``<=`` as equivalent to ``==`` +* treat ``>`` and ``<`` as always being False + +For ``Set of String`` fields, as there is no marker syntax for set literals, +the only valid operations are ``in`` and ``not in`` comparisons with a user +supplied string literal as the left operand. Publishing tools SHOULD emit an +error if environment markers attempt to use any other comparison operations on +these fields and index servers MAY disallow uploads containing such environment +markers, while locking and installation tools SHOULD treat such operations as +always being False. + +For ``Version`` fields, the comparison operations are defined by the +:ref:`Version specifier specification ` when either both +the marker field value and the user supplied constant can be parsed as valid +version specifiers or the ``===`` arbitrary equivalence comparison operator +is used. When an operator other than ``===`` is used, publishing tools SHOULD +emit an error if the user supplied constant cannot be parsed as a valid version +specifier, index servers MAY disallow uploads containing such environment +markers, while locking and installation tools MAY either emit an error or else +fall back to ``String`` field comparison logic if either the marker field value +or the user supplied constant cannot be parsed as a valid version specifier. +Note that ``in`` and ``not in`` containment checks are NOT valid for ``Version`` +fields and publishing tools SHOULD emit an error, index servers MAY disallow +uploads containing such environment markers, while locking and installation +tools MAY treat them as always being False. + +For ``Version | String`` fields, comparison operations are defined as they are +for ``Version`` fields, while ``in`` and ``not in`` containment checks are +defined as they are for ``String`` fields. However, there is no consistent +cross-platform expectation that the parsing of the marker field value or the +user supplied constant as a valid version will succeed, so tools SHOULD fall +back to processing the field as a ``String`` field if parsing either value as a +version fails. Tools MAY emit a warning if the field is expected to contain a +valid version on a given platform but does not in fact do so. Tools SHOULD NOT +unconditionally treat such fields as ``String`` fields, as doing so may give +incorrect answers for environment markers that are appropriately scoped +to the relevant platforms before performing a version based comparison. + + +Composing marker expressions +'''''''''''''''''''''''''''' + +More complex marker expressions may be composed using the ``and`` and ``or`` +logical operators. Parentheses may be used as necessary to control operand +precedence (with all comparison operations having a higher precedence). + +For example:: + + sys_platform == "ios" or sys_platform == "darwin" + sys_platform == "linux" and "SMP" in platform_version + sys_platform == "darwin" and platform_release >= "12" + +Python's comparison chaining (such as ``3.4 < python_version < 3.9``) is NOT +supported in environment markers (such expressions must instead be written out +as two separate comparisons joined by ``and``). + +User supplied constants +''''''''''''''''''''''' + +User supplied constants are always given as strings within either ``'`` or +``"`` quote marks. Triple-quoted multi-line strings are NOT permitted. + +Backslash escapes are not specified, although tools MAY support them. +They are not included in the specification because they add complexity and +there is currently no known need for treating user supplied constants as +anything other than either opaque strings or valid version specifiers. + +Similarly, non-ASCII character support is not specified, but tools MAY accept +them (usually based on the text encoding of the file or stream containing the +dependency specifier). This may be revisited in the future if it becomes more +common for the runtime variables typically referenced in environment markers to +contain non-ASCII text that users wish to perform comparisons against. + +Unknown marker fields +''''''''''''''''''''' + +References to unknown marker fields SHOULD render a package version ineligible +for installation or inclusion in a locked dependency tree rather than resulting +in a comparison that evaluates to True or False. This is so that published +package versions with unknown marker fields are either ignored when resolving +dependencies or emit a descriptive installation failure, rather than producing +an apparently successful installation that then fails at runtime due to missing +dependencies (if the unknown marker is treated as False) or a potentially +cryptic installation failure of a dependency that is not valid for the +current platform (if the unknown marker is treated as True). Variables whose value cannot be calculated on a given Python implementation -should evaluate to ``0`` for versions, and an empty string for all other -variables. +should evaluate to ``0`` for ``Version`` fields, and an empty string for all +other variables (including ``Version | String`` fields). + +.. _dependency-specifiers-environment-marker-fields: +.. _environment-marker-fields: -The "extra" variable is special. It is used by wheels to signal which -specifications apply to a given extra in the wheel ``METADATA`` file, but -since the ``METADATA`` file is based on a draft version of :pep:`426`, there is -no current specification for this. Regardless, outside of a context where this -special handling is taking place, the "extra" variable should result in an -error like all other unknown variables. +Defined environment marker fields +''''''''''''''''''''''''''''''''' -The "extras" and "dependency_groups" variables are also special. They are used -to specify any requested extras or dependency groups when installing from a lock -file. Outside of the context of lock files, these two variables should result in -an error like all other unknown variables. +Unless otherwise noted below, marker evaluation environments MUST support all +of the following marker fields: .. list-table:: :header-rows: 1 @@ -247,7 +363,7 @@ an error like all other unknown variables. * - Marker - Python equivalent - Type - - Sample values + - Sample values & notes * - ``os_name`` - :py:data:`os.name` - String @@ -255,61 +371,110 @@ an error like all other unknown variables. * - ``sys_platform`` - :py:data:`sys.platform` - String - - ``linux``, ``linux2``, ``darwin``, ``java1.8.0_51`` (note that "linux" - is from Python3 and "linux2" from Python2) + - ``linux``, ``win32``, ``darwin``, ``java1.8.0_51`` + (note that this is the most well defined field for use when declaring + platform specific dependencies) * - ``platform_machine`` - :py:func:`platform.machine()` - String - - ``x86_64`` + - ``x86_64``, ``aarch64``, ``AMD64``, ``arm64`` + (note that this value is provided by the operating system, so the same + CPU architecture may use different strings on different platforms) * - ``platform_python_implementation`` - :py:func:`platform.python_implementation()` - String - - ``CPython``, ``Jython`` + - ``CPython``, ``PyPy`` * - ``platform_release`` - :py:func:`platform.release()` - - String + - Version | String - ``3.14.1-x86_64-linode39``, ``14.5.0``, ``1.8.0_51`` + (may be a valid version field, for example on macOS/darwin) * - ``platform_system`` - :py:func:`platform.system()` - String - ``Linux``, ``Windows``, ``Java`` * - ``platform_version`` - :py:func:`platform.version()` - - String + - Version | String - ``#1 SMP Fri Apr 25 13:07:35 EDT 2014`` ``Java HotSpot(TM) 64-Bit Server VM, 25.51-b03, Oracle Corporation`` ``Darwin Kernel Version 14.5.0: Wed Jul 29 02:18:53 PDT 2015; root:xnu-2782.40.9~2/RELEASE_X86_64`` + ``13`` + (may be a valid version field, for example on iOS or Android) * - ``python_version`` - ``'.'.join(platform.python_version_tuple()[:2])`` - :ref:`Version ` - - ``3.4``, ``2.7`` + - ``3.9``, ``3.15`` * - ``python_full_version`` - :py:func:`platform.python_version()` - :ref:`Version ` - - ``3.4.0``, ``3.5.0b1`` + - ``3.10.12``, ``3.15.0a1`` * - ``implementation_name`` - :py:data:`sys.implementation.name ` - String - - ``cpython`` + - ``cpython``, ``pypy`` * - ``implementation_version`` - see definition below - :ref:`Version ` - - ``3.4.0``, ``3.5.0b1`` + - ``3.10.12``, ``7.3.17`` + (examples are for CPython and PyPy respectively) * - ``extra`` - - An error except when defined by the context interpreting the - specification. - - String + - Used to indicate optional dependencies in project dependency metadata. + An error except when defined by the context interpreting the + specifier. + - Special (see below) - ``toml`` + (publishing tools SHOULD permit use of this field) * - ``extras`` - - An error except when defined by the context interpreting the - specification. + - Used to indicate optional public dependencies in lock files. An error + except when defined by the context interpreting the specifier. - Set of strings - ``{"toml"}`` + (publishing tools SHOULD NOT permit use of this field and index servers + SHOULD NOT accept uploads containing such environment markers) * - ``dependency_groups`` - - An error except when defined by the context interpreting the - specification. + - Used to indicate optional project internal dependencies in lock files. + An error except when defined by the context interpreting the + specifier. - Set of strings - ``{"test"}`` + (publishing tools SHOULD NOT permit use of this field and index servers + SHOULD NOT accept uploads containing such environment markers) + +For backwards compatibility with older locking and installation tools, the +``extras`` and ``dependency_groups`` fields are currently only valid for use in +``packages.marker`` fields in :ref:`lock files `. For these +comparisons, the ``extras`` and ``dependency_groups`` sets used for the marker +evaluation refer to the *currently selected* extras and dependency groups when +installing from the lock file, not the full set of defined extras and dependency +groups listed in the corresponding top level lock file fields. The interface +for selecting which extras and dependency groups to install is tool dependent. +Publishing tools SHOULD emit an error if projects attempt to reference the +``extras`` or ``dependency_groups`` fields in their published dependency +declaration metadata, and index servers SHOULD NOT accept uploads referencing +these fields. Outside lock file processing, marker evaluation environments +DO NOT need to define these fields. + +The ``extra`` field is also special, as it expects set-like behaviour, but +predates the addition of ``Set of strings`` as a defined marker field type. +Accordingly, ``extra == "name"`` in a dependency declaration is similar to +``"name" in extras``, while ``extra != "name"`` is similar to +``"name" not in extras``. For dependency marker evaluations, the set of extra +names used for these comparisons is the full set of requested extras for *that +particular package*, whether requested directly in a top level dependency +declaration, or indirectly in a transitive dependency declaration. Other +comparison operations on ``extra`` are not defined and publishing tools SHOULD +emit an error, index servers MAY disallow uploads containing such environment +markers, while locking and installation tools SHOULD evaluate them as False. + +Unlike the newer ``extras`` field, environment markers using this field SHOULD +be accepted by both publishing tools and index servers. Marker evaluation +environments intended for project dependency declarations will typically need +to handle evaluation of ``extra`` field comparisons, while other evaluations +of environment markers will not generally need to do so. The legacy ``extra`` +comparison syntax is NOT permitted in lock file ``packages.marker`` fields, +and installation tools SHOULD reject lock files containing such comparisons as +invalid. The ``implementation_version`` marker variable is derived from :py:data:`sys.implementation.version `: @@ -328,9 +493,6 @@ The ``implementation_version`` marker variable is derived from else: implementation_version = "0" -This environment markers section, initially defined through :pep:`508`, supersedes the environment markers -section in :pep:`345`. - .. _dependency-specifiers-grammar: Complete Grammar @@ -512,6 +674,8 @@ A test program - if the grammar is in a string ``grammar``: print("%s -> %s" % (test, parsed)) +.. _dependency-specifier-history: + History ======= @@ -521,16 +685,28 @@ History ``'.'.join(platform.python_version_tuple()[:2])``, to accommodate potential future versions of Python with 2-digit major and minor versions (e.g. 3.10). [#future_versions]_ +- March 2022: Standardised the normalization of extra names at publication time + (for core metadata 2.3 and later) through :pep:`685` - June 2024: The definition of ``version_many`` was changed to allow trailing commas, matching with the behavior of the Python implementation that has been in use since late 2022. -- April 2025: Added ``extras`` and ``dependency_groups`` for +- April 2025: Added ``extras`` and ``dependency_groups`` marker field for :ref:`lock-file-spec` as approved through :pep:`751`. - August 2025: The suggested name validation regex was fixed to match the field specification (it previously finished with ``$`` instead of ``\Z``, incorrectly permitting trailing newlines) -- December 2025: Ensure ``===`` before ``==`` in grammar, to allow arbitrary +- December 2025: Ensure ``===`` is before ``==`` in grammar, to allow arbitrary equality comparisons to be parsed. +- January 2026: Amend the definition of environment marker comparison operations + to restrict version comparison semantics to fields where they make sense, + make extra name restrictions more explicit, adjust the way ordered comparisons + are defined for strings, and make the fallback from version comparisons to + string comparisons when version parsing fails optional. Also provide different + tool behaviour recommendations for publishing tools vs installation tools. + This brought the nominal specification into line with the way tools actually + work. [#marker_comparison_logic]_ +- January 2026: fix outdated references to other documents that were + inadvertently retained from :pep:`508` References @@ -546,6 +722,9 @@ References definition of Environment Marker Variable ``python_version`` (https://github.com/python/peps/issues/560) +.. [#marker_comparison_logic] Resolving inconsistencies between actual tool + behavior and the nominal definitions of environment marker field comparisons + (https://discuss.python.org/t/spec-change-bugfix-dependency-specifiers-simplification-pep-508/105203) .. _python-version-change: https://mail.python.org/pipermail/distutils-sig/2018-January/031920.html diff --git a/source/specifications/entry-points.rst b/source/specifications/entry-points.rst index dea039492..9e59862aa 100644 --- a/source/specifications/entry-points.rst +++ b/source/specifications/entry-points.rst @@ -106,8 +106,7 @@ Within a value, readers must accept and ignore spaces (including multiple consecutive spaces) before or after the colon, between the object reference and the left square bracket, between the extra names and the square brackets and colons delimiting them, and after the right square bracket. The syntax for -extras is formally specified as part of :pep:`508` (as ``extras``) and -restrictions on values specified in :pep:`685`. +extras is formally specified in :ref:`dependency-specifiers`. For tools writing the file, it is recommended only to insert a space between the object reference and the left square bracket. @@ -166,6 +165,8 @@ History - October 2017: This specification was written to formalize the existing entry points feature of setuptools (discussion_). +- January 2026: Replaced outdated direct references to :pep:`508` and + :pep:`685` with a reference to :ref:`dependency-specifiers`. .. _discussion: https://mail.python.org/pipermail/distutils-sig/2017-October/031585.html diff --git a/source/specifications/inline-script-metadata.rst b/source/specifications/inline-script-metadata.rst index 6fa832a3e..f9df2f0f5 100644 --- a/source/specifications/inline-script-metadata.rst +++ b/source/specifications/inline-script-metadata.rst @@ -70,6 +70,17 @@ and the regular expression, the text specification takes precedence. Tools MUST NOT read from metadata blocks with types that have not been standardized by this specification. +Note that the specification only requires that *top-level* comment blocks are +recognised as containing metadata. However, parsing Python code is non-trivial, +and therefore: + +* Tools MAY choose to do a simple textual scan, rather than a full Python parse. +* As a result of the previous point, the behaviour of scripts that contain data + that looks like metadata within another Python construct such as a multi-line + string is tool-dependent and should not be relied on. +* The canonical regular expression provided above is an example of an + implementation that does a simple textual scan. + script type ----------- diff --git a/source/specifications/pyproject-toml.rst b/source/specifications/pyproject-toml.rst index 20e055327..314dcc7b4 100644 --- a/source/specifications/pyproject-toml.rst +++ b/source/specifications/pyproject-toml.rst @@ -114,6 +114,13 @@ by the metadata). Dynamic metadata is listed via the ``dynamic`` key (defined later in this specification) and represents metadata that a tool will later provide. +A key whose value is a list or a table of arbitrary entries MAY be +specified statically *and* listed in ``dynamic`` at the same time. In +that case the entries given statically are fixed and a build back-end +MAY only *append* further entries to them; the back-end MUST NOT +remove, reorder, or modify any statically-specified entries. See the +:ref:`dynamic ` key for details. + The lack of a ``[project]`` table implicitly means the :term:`build backend ` will dynamically provide all keys. @@ -215,7 +222,7 @@ If the file path ends in a case-insensitive ``.md`` suffix, then tools MUST assume the content-type is ``text/markdown``. If the file path ends in a case-insensitive ``.rst``, then tools MUST assume the content-type is ``text/x-rst``. If a tool recognizes more extensions -than this PEP, they MAY infer the content-type for the user without +than this specification, it MAY infer the content-type for the user without specifying this key as ``dynamic``. For all unrecognized suffixes when a content-type is not provided, tools MUST raise an error. @@ -447,34 +454,62 @@ be ambiguous in the face of ``[project.scripts]`` and .. _pyproject-toml-dependencies: -.. _pyproject-toml-optional-dependencies: -``dependencies``/``optional-dependencies`` ------------------------------------------- +``dependencies`` +---------------- -- TOML_ type: Array of :pep:`508` strings (``dependencies``), and a - table with values of arrays of :pep:`508` strings - (``optional-dependencies``) +- TOML_ type: Array of :ref:`dependency specifier ` + strings (``dependencies``) - Corresponding :ref:`core metadata ` field: - :ref:`Requires-Dist ` and - :ref:`Provides-Extra ` + :ref:`Requires-Dist ` -The (optional) dependencies of the project. +``dependencies`` lists the expected dependencies of the project as an +array of strings. -For ``dependencies``, it is a key whose value is an array of strings. Each string represents a dependency of the project and MUST be -formatted as a valid :pep:`508` string. Each string maps directly to -a :ref:`Requires-Dist ` entry. +formatted as a valid :ref:`dependency specifier `. + +Each string maps directly to a +:ref:`Requires-Dist ` entry. + +Dependencies listed in this array are always considered +for installation, but may still contain environment markers that cause them +to be skipped in some environments. + + +.. _pyproject-toml-optional-dependencies: + +``optional-dependencies`` +------------------------- + +- TOML_ type: table with string keys mapping to arrays of + :ref:`dependency specifier ` strings (``optional-dependencies``) +- Corresponding :ref:`core metadata ` fields: + :ref:`Requires-Dist ` and + :ref:`Provides-Extra ` -For ``optional-dependencies``, it is a table where each key specifies -an extra and whose value is an array of strings. The strings of the -arrays must be valid :pep:`508` strings. The keys MUST be valid values +``optional-dependencies`` is a table where each key specifies +an extra and whose value is an array of strings using the same format as the +``dependencies`` array (the strings in the +arrays must be valid :ref:`dependency specifiers `). + +The keys MUST be valid values for :ref:`Provides-Extra `. Each value in the array thus becomes a corresponding :ref:`Requires-Dist ` entry for the matching :ref:`Provides-Extra ` metadata. +The optionality of these dependencies is recorded by modifying the environment +marker clause on the related ``Requires-Dist`` entries to check the extra name. +Optional dependencies are thus only considered for installation if installation +if the associated extra name is requested. + +Dependency specifiers in an extra may self-reference other extras from the +current project (e.g. ``all = ["your-project-name[gui, cli]"]``). See +:ref:`self-referential extras ` for an example. +Most package managers now support this kind of extra, including +:ref:`pip`, :ref:`uv`, :ref:`poetry`, :ref:`hatch`, :ref:`pdm` and :ref:`pipenv`. .. _pyproject-toml-import-names: @@ -596,8 +631,9 @@ provided via tooling later on. field as "Optional", the metadata MAY list it in ``dynamic`` if the expectation is a build back-end will provide the data for the key later. -- Build back-ends MUST raise an error if the metadata specifies a - key statically as well as being listed in ``dynamic``. +- Build back-ends MUST raise an error if the metadata specifies a key + statically as well as being listed in ``dynamic``, *unless* the key + represents a list or arbitrary table that can be extended, listed below. - If the metadata does not list a key in ``dynamic``, then a build back-end CANNOT fill in the requisite metadata on behalf of the user (i.e. ``dynamic`` is the only way to allow a tool to fill in @@ -607,6 +643,35 @@ provided via tooling later on. the data for it (omitting the data, if determined to be the accurate value, is acceptable). +A key whose value is a list or a table of arbitrary entries MAY be +specified statically and listed in ``dynamic`` simultaneously. The +keys fitting that description are: + +- ``authors`` +- ``classifiers`` +- ``dependencies`` +- ``entry-points`` +- ``gui-scripts`` +- ``import-names`` +- ``import-namespaces`` +- ``keywords`` +- ``license-files`` +- ``maintainers`` +- ``optional-dependencies`` +- ``scripts`` +- ``urls`` + +When such a key is specified both statically and listed in +``dynamic``: + +- A build back-end MAY only *append* entries to the value; it MUST NOT + remove, reorder, or modify any statically-specified entries. For + tables (such as ``optional-dependencies`` or ``entry-points``) this + means a back-end MAY add new keys and MAY append to the values of + existing keys (in the case of a list), but MUST NOT change or remove the + entries given statically. +- A build back-end SHOULD raise an error if a key is listed in + ``dynamic`` and it does not support extending that key. .. _pyproject-tool-table: @@ -647,4 +712,14 @@ History - October 2025: The ``import-names`` and ``import-namespaces`` keys were added through :pep:`794`. +- January 2026: Replaced outdated direct reference to :pep:`508` with a + reference to :ref:`dependency-specifiers`. + +- May 2026: Allowed list and table keys to be specified statically as well + as listed in ``dynamic``, with build back-ends only able to append + entries, through :pep:`808`. + +- August 2026: Document self-referential extra as a supported feature by many + modern package managers of Python. + .. _TOML: https://toml.io diff --git a/source/specifications/simple-repository-api.rst b/source/specifications/simple-repository-api.rst index d317db6f7..d7e14a4d3 100644 --- a/source/specifications/simple-repository-api.rst +++ b/source/specifications/simple-repository-api.rst @@ -122,6 +122,15 @@ HTML Serialization .. _simple-repository-html-project-list: +.. important:: + + The HTML representation is considered "frozen" and is not expected + to be updated. Producers and consumers of the simple API + should prefer the :ref:`JSON representation `. + + See :pep:`833` for additional information about the HTML representation's + status. + The following constraints apply to all HTML serialized responses described in this spec: @@ -989,3 +998,4 @@ History * November 2024: provenance metadata in the HTML and JSON formats, in :pep:`740` * July 2025: project status markers in the HTML and JSON formats, in :pep:`792` * July 2025: layout changes (dedicated page for file yanking, introduce concepts before API details) +* June 2026: :pep:`833` formally "freezes" the HTML representation of the simple API diff --git a/source/specifications/source-distribution-format.rst b/source/specifications/source-distribution-format.rst index 9ac93be7b..b877e87d5 100644 --- a/source/specifications/source-distribution-format.rst +++ b/source/specifications/source-distribution-format.rst @@ -74,7 +74,7 @@ at their respective paths relative to the root directory of the sdist No other content of a sdist is required or defined. Build systems can store whatever information they need in the sdist to build the project. -The tarball should use the modern POSIX.1-2001 pax tar format, which specifies +The tarball must use the modern POSIX.1-2001 pax tar format, which specifies UTF-8 based file names. In particular, source distribution files must be readable using the standard library tarfile module with the open flag 'r:gz'. diff --git a/source/specifications/version-specifiers.rst b/source/specifications/version-specifiers.rst index e05422ce2..75093c2e2 100644 --- a/source/specifications/version-specifiers.rst +++ b/source/specifications/version-specifiers.rst @@ -172,9 +172,6 @@ identified by the public version identifier, but contains additional changes indexing and hosting upstream projects, it MUST NOT allow the use of local version identifiers. -Source distributions using a local version identifier SHOULD provide the -``python.integrator`` extension metadata (as defined in :pep:`459`). - Final releases --------------