Add SPDX 3.1

[bact]

Note

Merge #49 before this PR.

• Add SPDX 3.1 binding generation
• Build from bundled files first (for 3.1, use 3.1-dev as of 23 June 2026)

Main changes are in

• gen/generate-bindings to generate docstring that lists all SPDX model versions (will be used for API doc generation)
• src/spdx_python_model/__init__.py for SPDXDraftWarning that will warn user when importing a draft model
• The rest are copy of 3.0.1 and 3.1-dev models

File type	Canonical URL	Actual content comes from (saves these to use locally in spdx_model/)
RDF+SHACL	https://spdx.org/rdf/3.1/spdx-model.ttl	https://spdx.github.io/spdx-spec/v3.1/rdf/spdx-model.ttl
JSON-LD context file	https://spdx.org/rdf/3.1/spdx-context.jsonld	https://spdx.github.io/spdx-spec/v3.1/rdf/spdx-context.jsonld
JSON-LD serialization annotations	https://spdx.org/rdf/3.1/spdx-json-serialize-annotations.ttl	https://spdx.github.io/spdx-spec/v3.1/rdf/jsonld-annotations.ttl
JSON Schema	https://spdx.org/schema/3.1/spdx-json-schema.json	https://spdx.github.io/spdx-spec/v3.1/rdf/schema.json

[bact]

@JPEWdev @benjarobin Please see if this is an acceptable approach.

The idea is to allow wider early test of draft models, in this case SPDX 3.1:

• Model files are bundled in spdx_model/, shipped with the package, to allow offline build.
• "3.1" is included in SPDX_VERSIONS_DRAFT variable of gen/generate-bindings script (manually); this will be used later to indicate that "3.1" is still in draft stage
• When generating __init__.py of .bindings submodule, list all available versions, their sources, and status (draft or not) in the submodule docstring. So the user can know about the draft status. (see demo https://bact.github.io/spdx-python-model/doc/dev/spdx_python_model/bindings.html)
• When user import v3_1 submodule, SPDXDraftWarning (subclass of FutureWarning) will be raised once.

Once SPDX 3.1 is released, we can move "3.1" to SPDX_VERSIONS_RELEASE, release spdx-python-model, then SPDXDraftWarning will stop raising.

Does this make sense or anything that you feel they should be adjusted?

--

Note that currently it is already possible to test draft models by using SHACL2CODE_SPDX_DIR but that requires some setup (not just pip install).

With the ability to pin a snapshot of a model in the bundle, we can also orchestrate tests with RC2 once it is available.

"Install spdx-python-model 0.0.8 to test SPDX 3.1-RC2" is a convenient message to spread.

[bact]

Note: Once JPEWdev/shacl2code#124 is merged and shacl2code release a new version with it, it will also be possible to use Ontology.is_prelease information to raise SPDXDraftWarning (without the need to maintain SPDX_VERSIONS_DRAFT in gen/generate-bindings) -- or actually the binding will automatically raise the FutureWarning by itself.