feat(core-cython-hello): Add project using add_custom_command() and cython

Author: jcfr

noxfile.py

@@ -7,6 +7,7 @@
     "hello-cpp",
     "hello-pybind11",
     "hello-cython",
+    "core-cython-hello",
 ]
 if not sys.platform.startswith("win"):
     hello_list.extend(

projects/core-cython-hello/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.15...3.26)
+
+project(${SKBUILD_PROJECT_NAME} VERSION ${SKBUILD_PROJECT_VERSION} LANGUAGES C)
+
+find_package(
+  Python
+  COMPONENTS Interpreter Development.Module
+  REQUIRED)
+find_program(CYTHON "cython")
+
+add_subdirectory(hello)

projects/core-cython-hello/hello/CMakeLists.txt

@@ -0,0 +1,14 @@
+add_custom_command(
+  OUTPUT _hello.c
+  DEPENDS _hello.pyx
+  COMMAND "${CYTHON}"
+    "${CMAKE_CURRENT_SOURCE_DIR}/_hello.pyx"
+    --output-file "${CMAKE_CURRENT_BINARY_DIR}/_hello.c"
+  VERBATIM
+  )
+
+Python_add_library(_hello
+  MODULE "${CMAKE_CURRENT_BINARY_DIR}/_hello.c"
+  WITH_SOABI)
+
+install(TARGETS _hello LIBRARY DESTINATION ${SKBUILD_PROJECT_NAME})

projects/core-cython-hello/hello/__init__.py

@@ -0,0 +1,3 @@
+from ._hello import elevation, hello
+
+__all__ = ("hello", "elevation")

projects/core-cython-hello/hello/_hello.pyx

@@ -0,0 +1,8 @@
+
+cpdef void hello(str strArg):
+    "Prints back 'Hello <param>', for example example: hello.hello('you')"
+    print("Hello, {}!".format(strArg))
+
+cpdef long elevation():
+    "Returns elevation of Nevado Sajama."
+    return 21463L

projects/core-cython-hello/pyproject.toml

@@ -0,0 +1,20 @@
+[build-system]
+requires = ["scikit-build-core[pyproject]", "cython"]
+build-backend = "scikit_build_core.build"
+
+[project]
+name = "hello"
+version = "1.2.3"
+authors = [
+  { name = "The scikit-build team" },
+]
+description = "a minimal example package (cython version)"
+requires-python = ">=3.8"
+classifiers = [
+  "License :: OSI Approved :: MIT License",
+]
+dependencies = []
+
+[tool.scikit-build]
+cmake.source-dir = "."
+minimum-version = "0.5"

projects/core-cython-hello/tests/test_hello_cython.py

@@ -0,0 +1,11 @@
+import hello
+
+
+def test_hello(capfd):
+    hello.hello("World")
+    captured = capfd.readouterr()
+    assert captured.out == "Hello, World!\n"
+
+
+def test_elevation():
+    assert hello.elevation() == 21463