6 files changed, 63 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..9d22eb4
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+*.o
+*.so
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..44c43bf
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,12 @@
+all: sum.o sum_module.so
+
+sum.o:
+        cc -c -o sum.o sum.c
+
+sum_module.so:
+        cc -shared -I/usr/include/python3.12 -o sum_module.so sum.o sum_module.c
+
+clean:
+        rm -rf *.o *.so
+
+.PHONY: all clean
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..071d2e7
--- /dev/null
+++ b/README.md
@@ -0,0 +1,16 @@
+# A tiny demo for a Python module in C
+
+This repo contains a Python module written in C with only one function.
+
+Works on my machine™. To make it works on yours:
+
+1. Install the python development package. It is usually called `python3-dev`
+   or `python3-devel`.
+2. Compile this module with `make`.
+3. Open `python` and enjoy!
+
+```
+>>> import sum_module
+>>> sum_module.sum_from_c(23, 19)
+42
+```
diff --git a/sum.c b/sum.c
new file mode 100644
index 0000000..d3603fc
--- /dev/null
+++ b/sum.c
@@ -0,0 +1 @@
+int sum(int a, int b) { return a+b; }
diff --git a/sum.h b/sum.h
new file mode 100644
index 0000000..3813423
--- /dev/null
+++ b/sum.h
@@ -0,0 +1 @@
+int sum(int, int);
diff --git a/sum_module.c b/sum_module.c
new file mode 100644
index 0000000..5f55747
--- /dev/null
+++ b/sum_module.c
@@ -0,0 +1,31 @@
+#include "sum.h"
+
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+
+static PyObject *csum(PyObject *self, PyObject *args) {
+        int a, b, result;
+
+        if (!PyArg_ParseTuple(args, "ii", &a, &b))
+                return NULL;
+
+        result = sum(a, b);
+        return PyLong_FromLong(result);
+}
+
+static PyMethodDef SumMethods[] = {
+        { "sum_from_c", csum, METH_VARARGS, "Sum two integers." },
+        { NULL, NULL, 0, NULL }
+};
+
+static struct PyModuleDef summodule = {
+        PyModuleDef_HEAD_INIT,
+        "sum",
+        NULL,
+        -1,
+        SumMethods
+};
+
+PyMODINIT_FUNC PyInit_sum_module(void) {
+        return PyModule_Create(&summodule);
+}