Mastering Python Second Edition Release Code

CH_18_packaging/T_04_C_extensions/setup.py

@@ -0,0 +1,23 @@
+import pathlib
+import setuptools
+
+# Get the current directory
+PROJECT_PATH = pathlib.Path(__file__).parent
+
+
+sum_of_squares = setuptools.Extension('sum_of_squares', sources=[
+    # Get the relative path to sum_of_squares.c
+    str(PROJECT_PATH / 'sum_of_squares.c'),
+])
+
+
+if __name__ == '__main__':
+    setuptools.setup(
+        name='T_04_C_extensions',
+        version='0.1.0',
+        packages=setuptools.find_packages(),
+        url='https://wol.ph/',
+        author='Rick van Hattem',
+        author_email='wolph@wol.ph',
+        ext_modules=[sum_of_squares],
+    )

CH_18_packaging/T_04_C_extensions/sum_of_squares.c

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+#include <Python.h>
+
+static PyObject* sum_of_squares(PyObject *self, PyObject
+        *args){
+    /* Declare the variables */
+    int n;
+    int total = 0;
+
+    /* Parse the arguments */
+    if(!PyArg_ParseTuple(args, "i", &n)){
+        return NULL;
+    }
+
+    /* The actual summing code */
+    for(int i=0; i<n; i++){
+        if((i * i) < n){
+            total += i * i;
+        }else{
+            break;
+        }
+    }
+
+    /* Return the number but convert it to a Python object first
+     */
+    return PyLong_FromLong(total);
+}
+
+static PyMethodDef methods[] = {
+    /* Register the function */
+    {"sum_of_squares", sum_of_squares, METH_VARARGS,
+     "Sum the perfect squares below n"},
+    /* Indicate the end of the list */
+    {NULL, NULL, 0, NULL},
+};
+
+static struct PyModuleDef module = {
+    PyModuleDef_HEAD_INIT,
+    "sum_of_squares", /* Module name */
+    NULL, /* Module documentation */
+    -1, /* Module state, -1 means global. This parameter is
+           for sub-interpreters */
+    methods,
+};
+
+/* Initialize the module */
+PyMODINIT_FUNC PyInit_sum_of_squares(void){
+    return PyModule_Create(&module);
+}
+