gh-111489: Add PyTuple_FromArray() function

Doc/c-api/tuple.rst

@@ -37,6 +37,19 @@ Tuple Objects
  or ``NULL`` with an exception set on failure.
 
 
+.. c:function:: PyObject* PyTuple_FromArray(PyObject *const *array, Py_ssize_t size)
+
+ Create a tuple of *size* items and copy references from *array* to the new
+ tuple.
+
+ *array* can be NULL if *size* is ``0``.
+
+ On success, return a new reference.
+ On error, set an exception and return ``NULL``.
+
+ .. versionadded:: next
+
+
 .. c:function:: PyObject* PyTuple_Pack(Py_ssize_t n, ...)
 
  Return a new tuple object of size *n*,

Doc/whatsnew/3.15.rst

@@ -852,6 +852,9 @@ New features
 
  (Contributed by Victor Stinner in :gh:`129813`.)
 
+* Add :c:func:`PyTuple_FromArray` to create a :class:`tuple` from an array.
+ (Contributed by Victor Stinner in :gh:`111489`.)
+
 
 Porting to Python 3.15
 ----------------------

Include/cpython/tupleobject.h

@@ -38,3 +38,7 @@ PyTuple_SET_ITEM(PyObject *op, Py_ssize_t index, PyObject *value){
 }
 #define PyTuple_SET_ITEM(op, index, value) \
  PyTuple_SET_ITEM(_PyObject_CAST(op), (index), _PyObject_CAST(value))
+
+PyAPI_FUNC(PyObject*) PyTuple_FromArray(
+ PyObject *const *array,
+ Py_ssize_t size);

Include/internal/pycore_tuple.h

@@ -23,7 +23,9 @@ extern PyStatus _PyTuple_InitGlobalObjects(PyInterpreterState *);
 
 #define _PyTuple_ITEMS(op) _Py_RVALUE(_PyTuple_CAST(op)->ob_item)
 
-PyAPI_FUNC(PyObject *)_PyTuple_FromArray(PyObject *const *, Py_ssize_t);
+// Alias for backward compatibility
+#define _PyTuple_FromArray PyTuple_FromArray
+
 PyAPI_FUNC(PyObject *)_PyTuple_FromStackRefStealOnSuccess(const union _PyStackRef *, Py_ssize_t);
 PyAPI_FUNC(PyObject *)_PyTuple_FromArraySteal(PyObject *const *, Py_ssize_t);
 

Lib/test/test_capi/test_tuple.py

@@ -62,6 +62,28 @@ def test_tuple_new(self):
  self.assertRaises(SystemError, tuple_new, PY_SSIZE_T_MIN)
  self.assertRaises(MemoryError, tuple_new, PY_SSIZE_T_MAX)
 
+ def test_tuple_fromarray(self):
+ # Test PyTuple_FromArray()
+ tuple_fromarray = _testcapi.tuple_fromarray
+
+ tup = tuple([i] for i in range(5))
+ copy = tuple_fromarray(tup)
+ self.assertEqual(copy, tup)
+
+ tup = ()
+ copy = tuple_fromarray(tup)
+ self.assertIs(copy, tup)
+
+ copy = tuple_fromarray(NULL, 0)
+ self.assertIs(copy, ())
+
+ with self.assertRaises(SystemError):
+ tuple_fromarray(NULL, -1)
+ with self.assertRaises(SystemError):
+ tuple_fromarray(NULL, PY_SSIZE_T_MIN)
+ with self.assertRaises(MemoryError):
+ tuple_fromarray(NULL, PY_SSIZE_T_MAX)
+
  def test_tuple_pack(self):
  # Test PyTuple_Pack()
  pack = _testlimitedcapi.tuple_pack

Misc/NEWS.d/next/C_API/2025-10-07-12-51-32.gh-issue-111489.LCKKlg.rst

@@ -0,0 +1,2 @@
+Add :c:func:`PyTuple_FromArray` to create a :class:`tuple` from an array.
+Patch by Victor Stinner.

Modules/_testcapi/tuple.c

@@ -104,12 +104,40 @@ _check_tuple_item_is_NULL(PyObject *Py_UNUSED(module), PyObject *args)
 }
 
 
+static PyObject *
+tuple_fromarray(PyObject* Py_UNUSED(module), PyObject *args)
+{
+ PyObject *src;
+ Py_ssize_t size = UNINITIALIZED_SIZE;
+ if (!PyArg_ParseTuple(args, "O|n", &src, &size)){
+ return NULL;
+ }
+ if (src != Py_None && !PyTuple_Check(src)){
+ PyErr_SetString(PyExc_TypeError, "expect a tuple");
+ return NULL;
+ }
+
+ PyObject **items;
+ if (src != Py_None){
+ items = &PyTuple_GET_ITEM(src, 0);
+ if (size == UNINITIALIZED_SIZE){
+ size = PyTuple_GET_SIZE(src);
+ }
+ }
+ else{
+ items = NULL;
+ }
+ return PyTuple_FromArray(items, size);
+}
+
+
 static PyMethodDef test_methods[] ={
 {"tuple_get_size", tuple_get_size, METH_O},
 {"tuple_get_item", tuple_get_item, METH_VARARGS},
 {"tuple_set_item", tuple_set_item, METH_VARARGS},
 {"_tuple_resize", _tuple_resize, METH_VARARGS},
 {"_check_tuple_item_is_NULL", _check_tuple_item_is_NULL, METH_VARARGS},
+{"tuple_fromarray", tuple_fromarray, METH_VARARGS},
 {NULL},
 };
 

Objects/tupleobject.c

@@ -366,7 +366,7 @@ tuple_item(PyObject *op, Py_ssize_t i)
 }
 
 PyObject *
-_PyTuple_FromArray(PyObject *const *src, Py_ssize_t n)
+PyTuple_FromArray(PyObject *const *src, Py_ssize_t n)
 {
  if (n == 0){
  return tuple_get_empty();