Python notebooks

.gitignore

@@ -79,6 +79,9 @@ _build
 
 *.log
 
+*.lock
+conda/recipe/meta.yaml
+conda/recipe
 .vs/
 *.key
 
@@ -89,3 +92,6 @@ uv.lock
 *.bck
 *log
 *.claude
+.pixi/
+conda/recipe/meta.yaml
+conda/recipe/meta.yaml

.gitlab-ci.yml

@@ -2,6 +2,11 @@
 #
 # SPDX-License-Identifier: Unlicense
 
+stages:
+  - build
+  - test
+  - deploy
+
 # ============================================================
 #  GPU-specific images and runner configuration
 # ============================================================
@@ -76,15 +81,38 @@
 #  Job templates
 # ============================================================
 .build-and-test:
+  variables:
+    CMAKE_BUILD_PARALLEL_LEVEL: "3"
   script:
     - ./ci/lrz-gitlab/build-and-test.sh
 
 .benchmark:
   extends:
     - .setup-for-benchmarking
+  variables:
+    CMAKE_BUILD_PARALLEL_LEVEL: "3"
   script:
     - ./ci/lrz-gitlab/benchmark.sh
 
+.build-python-wheel:
+  variables:
+    CMAKE_BUILD_PARALLEL_LEVEL: "3"
+  before_script:
+    - python3 -m pip install --user --break-system-packages build
+  script:
+    - python3 -m build --wheel
+    - python3 ci/smoke_test_wheel.py
+  artifacts:
+    paths:
+      - dist/*.whl
+
+.pixi-python-package:
+  image: ghcr.io/prefix-dev/pixi:latest
+  variables:
+    CMAKE_BUILD_PARALLEL_LEVEL: "1"
+  before_script:
+    - pixi install --locked
+
 # ============================================================
 #  NeoN - testing jobs
 # ============================================================
@@ -126,3 +154,42 @@ benchmark-neon-intel:
     - .gpu-intel
     - .rules-neon-benchmarking
     - .benchmark
+
+# ============================================================
+#  NeoN - Python packaging job
+# ============================================================
+build-python-wheel-nvidia:
+  extends:
+    - .gpu-nvidia
+    - .rules-neon-testing
+    - .build-python-wheel
+
+build-python-wheel-pixi:
+  extends:
+    - .pixi-python-package
+  stage: build
+  script:
+    - pixi run -e build smoke-test
+  artifacts:
+    paths:
+      - dist/*.whl
+    expire_in: 1 week
+  rules:
+    - if: '$CI_COMMIT_TAG'
+    - if: '$CI_PIPELINE_SOURCE == "merge_request_event"'
+    - if: '$CI_COMMIT_BRANCH'
+
+publish-python-wheel-pypi:
+  extends:
+    - .pixi-python-package
+  stage: deploy
+  needs:
+    - job: build-python-wheel-pixi
+      artifacts: true
+  id_tokens:
+    PYPI_ID_TOKEN:
+      aud: pypi
+  script:
+    - pixi run -e release twine upload dist/*
+  rules:
+    - if: '$CI_COMMIT_TAG =~ /^v?[0-9]+\.[0-9]+\.[0-9]+$/'

README.md

@@ -63,6 +63,24 @@ We provide a set of unit tests which can be executed via ctest or
 
     cmake --build . --target test
 
+### Pixi Workspace
+
+For reproducible local development environments, NeoN can also be driven via
+`pixi.toml`. Pixi is used here as the environment and task runner, while the
+actual compilation and wheel creation still go through CMake and
+`python -m build`.
+
+Typical commands are:
+
+    pixi install                 # creates pixi.lock
+    pixi run -e build build      # configure + build with -j3
+    pixi run -e py312 test       # run ctest in the Python 3.12 environment
+    pixi run -e build wheel      # build a wheel without build isolation
+    pixi run -e build smoke-test # install the built wheel in an isolated venv and run test_neon_package.py
+
+The generated `pixi.lock` should be committed so CI uses pinned tooling across
+platforms.
+
 
 ## Integration with other CFD Frameworks
 

conda/recipe/README.md

@@ -0,0 +1,43 @@
+# Conda recipe for NeoN
+
+This recipe packages the NeoN Python bindings and ships the compiled extension
+(`neon/_neon*.so` on Linux/macOS, `neon/_neon*.pyd` on Windows).
+
+## Build locally
+
+```bash
+conda build conda/recipe
+```
+
+The recipe defaults to `CMAKE_BUILD_PARALLEL_LEVEL=2` to reduce memory pressure.
+Override it when needed:
+
+```bash
+CMAKE_BUILD_PARALLEL_LEVEL=1 conda build conda/recipe
+```
+
+Get the produced package path:
+
+```bash
+conda build conda/recipe --output
+```
+
+## Upload to anaconda.org
+
+```bash
+anaconda login
+anaconda upload "$(conda build conda/recipe --output)"
+```
+
+## Install and verify
+
+```bash
+conda install -c <your-channel> neon
+python -c "import neon; import neon._neon; print(neon.__version__)"
+```
+
+## Notes
+
+- The package build uses `pip install . --no-build-isolation --no-deps` with `scikit-build-core`.
+- Build requirements use Conda compilers to produce relocatable binaries.
+- Additional system/compiler requirements may be needed depending on your platform and accelerator setup.

conda/recipe/meta.yaml

@@ -0,0 +1,49 @@
+{% set name = "exasim-neon" %}
+{% set version = "0.1.0" %}
+
+package:
+  name: {{ name|lower }}
+  version: {{ version }}
+
+source:
+  path: ../../
+
+build:
+  number: 0
+  script:
+    - export CMAKE_BUILD_PARALLEL_LEVEL=${CMAKE_BUILD_PARALLEL_LEVEL:-1}
+    - {{ PYTHON }} -m pip install . -vv --no-build-isolation --no-deps
+
+requirements:
+  build:
+    - {{ compiler('cxx') }}
+    - cmake >=3.22
+    - ninja
+  host:
+    - python
+    - pip
+    - scikit-build-core >=0.11.0
+    - nanobind >=2.9.0
+    - nlohmann_json
+    - setuptools
+  run:
+    - python
+    - numpy >=1.19.0
+
+test:
+  requires:
+    - pip
+  imports:
+    - neon
+  commands:
+    - python -c "import neon; print(neon.__version__, neon.__has_serial__)"
+    - python -c "import neon._neon as ext; print('loaded', ext.__name__)"
+
+about:
+  home: https://github.com/exasim-project/NeoN
+  summary: Python bindings for the NeoN CFD framework
+  license: MIT
+
+extra:
+  recipe-maintainers:
+    - exasim-project