Add Py_fopen() and Py_fclose()

docs/api.rst

@@ -169,6 +169,14 @@ Python 3.14
 
    See `PyLong_FromUInt64() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong_FromUInt64>`__.
 
+.. c:function:: FILE* Py_fopen(PyObject *path, const char *mode)
+
+   See `Py_fopen() documentation <https://docs.python.org/dev/c-api/sys.html#c.Py_fopen>`__.
+
+.. c:function:: int Py_fclose(FILE *file)
+
+   See `Py_fclose() documentation <https://docs.python.org/dev/c-api/sys.html#c.Py_fclose>`__.
+
 
 Not supported:
 

docs/changelog.rst

@@ -1,6 +1,7 @@
 Changelog
 =========
 
+* 2025-01-06: Add ``Py_fopen()`` and ``Py_fclose()`` functions.
 * 2024-12-16: Add ``structmember.h`` constants:
 
   * ``Py_T_BOOL``

pythoncapi_compat.h

@@ -1933,6 +1933,47 @@ PyLongWriter_Finish(PyLongWriter *writer)
 #endif
 
 
+// gh-127350 added Py_fopen() and Py_fclose() to Python 3.14a4
+#if PY_VERSION_HEX < 0x030E00A4
+static inline FILE* Py_fopen(PyObject *path, const char *mode)
+{
+#if 0x030400A2 <= PY_VERSION_HEX && !defined(PYPY_VERSION)
+    extern FILE* _Py_fopen_obj(PyObject *path, const char *mode);
+    return _Py_fopen_obj(path, mode);
+#else
+    FILE *f;
+    PyObject *bytes;
+#if PY_VERSION_HEX >= 0x03000000
+    if (!PyUnicode_FSConverter(path, &bytes)) {
+        return NULL;
+    }
+#else
+    if (!PyString_Check(path)) {
+        PyErr_SetString(PyExc_TypeError, "except str");
+        return NULL;
+    }
+    bytes = Py_NewRef(path);
+#endif
+    const char *path_bytes = PyBytes_AS_STRING(bytes);
+
+    f = fopen(path_bytes, mode);
+    Py_DECREF(bytes);
+
+    if (f == NULL) {
+        PyErr_SetFromErrnoWithFilenameObject(PyExc_OSError, path);
+        return NULL;
+    }
+    return f;
+#endif
+}
+
+int Py_fclose(FILE *file)
+{
+    return fclose(file);
+}
+#endif
+
+
 #ifdef __cplusplus
 }
 #endif

tests/test_pythoncapi_compat_cext.c

@@ -2097,6 +2097,21 @@ test_structmember(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
 }
 
 
+static PyObject *
+test_file(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
+{
+    const char *filename = __FILE__;
+    PyObject *path = create_string(filename);
+
+    FILE *fp = Py_fopen(path, "rb");
+    Py_DECREF(path);
+    assert(fp != NULL);
+    Py_fclose(fp);
+
+    Py_RETURN_NONE;
+}
+
+
 static struct PyMethodDef methods[] = {
     {"test_object", test_object, METH_NOARGS, _Py_NULL},
     {"test_py_is", test_py_is, METH_NOARGS, _Py_NULL},
@@ -2144,6 +2159,7 @@ static struct PyMethodDef methods[] = {
     {"test_iter", test_iter, METH_NOARGS, _Py_NULL},
     {"test_long_stdint", test_long_stdint, METH_NOARGS, _Py_NULL},
     {"test_structmember", test_structmember, METH_NOARGS, _Py_NULL},
+    {"test_file", test_file, METH_NOARGS, _Py_NULL},
     {_Py_NULL, _Py_NULL, 0, _Py_NULL}
 };