pythongh-111696, PEP 737: Add PyType_GetFullyQualifiedName() function

Rewrite tests on type names in Python, they were written in C.

Doc/c-api/type.rst

@@ -185,6 +185,14 @@ Type Objects
 
    .. versionadded:: 3.11
 
+.. c:function:: PyObject* PyType_GetFullyQualifiedName(PyTypeObject *type)
+
+   Return the type's fully qualified name. Equivalent to
+   ``f"{type.__module__}.{type.__qualname__}"``, or ``type.__qualname__`` if
+   ``type.__module__`` is not a string or is equal to ``"builtins"``.
+
+   .. versionadded:: 3.13
+
 .. c:function:: void* PyType_GetSlot(PyTypeObject *type, int slot)
 
    Return the function pointer stored in the given slot. If the

Doc/whatsnew/3.13.rst

@@ -1649,6 +1649,12 @@ New Features
   between native integer types and Python :class:`int` objects.
   (Contributed by Steve Dower in :gh:`111140`.)
 
+* Add :c:func:`PyType_GetFullyQualifiedName` function to get the type's fully
+  qualified name. Equivalent to ``f"{type.__module__}.{type.__qualname__}"``,
+  or ``type.__qualname__`` if ``type.__module__`` is not a string or is equal
+  to ``"builtins"``.
+  (Contributed by Victor Stinner in :gh:`111696`.)
+
 
 Porting to Python 3.13
 ----------------------

Include/object.h

@@ -522,6 +522,9 @@ PyAPI_FUNC(void *) PyType_GetModuleState(PyTypeObject *);
 PyAPI_FUNC(PyObject *) PyType_GetName(PyTypeObject *);
 PyAPI_FUNC(PyObject *) PyType_GetQualName(PyTypeObject *);
 #endif
+#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x030D0000
+PyAPI_FUNC(PyObject *) PyType_GetFullyQualifiedName(PyTypeObject *);
+#endif
 #if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x030C0000
 PyAPI_FUNC(PyObject *) PyType_FromMetaclass(PyTypeObject*, PyObject*, PyType_Spec*, PyObject*);
 PyAPI_FUNC(void *) PyObject_GetTypeData(PyObject *obj, PyTypeObject *cls);

Lib/test/test_capi/test_misc.py

@@ -1100,21 +1100,65 @@ class Data(_testcapi.ObjExtraData):
         del d.extra
         self.assertIsNone(d.extra)
 
-    def test_get_type_module_name(self):
+    def test_get_type_name(self):
+        class MyType:
+            pass
+
+        from _testcapi import get_type_name, get_type_qualname, get_type_fullyqualname
+        from _testinternalcapi import get_type_module_name
+
         from collections import OrderedDict
         ht = _testcapi.get_heaptype_for_name()
-        for cls, expected in {
-            int: 'builtins',
-            OrderedDict: 'collections',
-            ht: '_testcapi',
-        }.items():
-            with self.subTest(repr(cls)):
-                modname = _testinternalcapi.get_type_module_name(cls)
-                self.assertEqual(modname, expected)
+        for cls, fullname, modname, qualname, name in (
+            (int,
+             'int',
+             'builtins',
+             'int',
+             'int'),
+            (OrderedDict,
+             'collections.OrderedDict',
+             'collections',
+             'OrderedDict',
+             'OrderedDict'),
+            (ht,
+             '_testcapi.HeapTypeNameType',
+             '_testcapi',
+             'HeapTypeNameType',
+             'HeapTypeNameType'),
+            (MyType,
+             f'{__name__}.CAPITest.test_get_type_name.<locals>.MyType',
+             __name__,
+             'CAPITest.test_get_type_name.<locals>.MyType',
+             'MyType'),
+        ):
+            with self.subTest(cls=repr(cls)):
+                self.assertEqual(get_type_fullyqualname(cls), fullname)
+                self.assertEqual(get_type_module_name(cls), modname)
+                self.assertEqual(get_type_qualname(cls), qualname)
+                self.assertEqual(get_type_name(cls), name)
 
+        # override __module__
         ht.__module__ = 'test_module'
-        modname = _testinternalcapi.get_type_module_name(ht)
-        self.assertEqual(modname, 'test_module')
+        self.assertEqual(get_type_fullyqualname(ht), 'test_module.HeapTypeNameType')
+        self.assertEqual(get_type_module_name(ht), 'test_module')
+        self.assertEqual(get_type_qualname(ht), 'HeapTypeNameType')
+        self.assertEqual(get_type_name(ht), 'HeapTypeNameType')
+
+        # override __name__ and __qualname__
+        MyType.__name__ = 'my_name'
+        MyType.__qualname__ = 'my_qualname'
+        self.assertEqual(get_type_fullyqualname(MyType), f'{__name__}.my_qualname')
+        self.assertEqual(get_type_module_name(MyType), __name__)
+        self.assertEqual(get_type_qualname(MyType), 'my_qualname')
+        self.assertEqual(get_type_name(MyType), 'my_name')
+
+        # override also __module__
+        MyType.__module__ = 'my_module'
+        self.assertEqual(get_type_fullyqualname(MyType), 'my_module.my_qualname')
+        self.assertEqual(get_type_module_name(MyType), 'my_module')
+        self.assertEqual(get_type_qualname(MyType), 'my_qualname')
+        self.assertEqual(get_type_name(MyType), 'my_name')
+
 
 @requires_limited_api
 class TestHeapTypeRelative(unittest.TestCase):

Misc/NEWS.d/next/C API/2024-03-14-15-17-11.gh-issue-111696.YmnvAi.rst

@@ -0,0 +1,4 @@
+Add :c:func:`PyType_GetFullyQualifiedName` function to get the type's fully
+qualified name. Equivalent to ``f"{type.__module__}.{type.__qualname__}"``, or
+``type.__qualname__`` if ``type.__module__`` is not a string or is equal to
+``"builtins"``. Patch by Victor Stinner.

Misc/stable_abi.toml

@@ -2496,3 +2496,5 @@
 [typedef.PyCFunctionFastWithKeywords]
     added = '3.13'
     # "abi-only" since 3.10.  (Same story as PyCFunctionFast.)
+[function.PyType_GetFullyQualifiedName]
+    added = '3.13'

Modules/_testcapimodule.c

@@ -597,83 +597,31 @@ get_heaptype_for_name(PyObject *self, PyObject *Py_UNUSED(ignored))
     return PyType_FromSpec(&HeapTypeNameType_Spec);
 }
 
+
 static PyObject *
-test_get_type_name(PyObject *self, PyObject *Py_UNUSED(ignored))
+get_type_name(PyObject *self, PyObject *type)
 {
-    PyObject *tp_name = PyType_GetName(&PyLong_Type);
-    assert(strcmp(PyUnicode_AsUTF8(tp_name), "int") == 0);
-    Py_DECREF(tp_name);
-
-    tp_name = PyType_GetName(&PyModule_Type);
-    assert(strcmp(PyUnicode_AsUTF8(tp_name), "module") == 0);
-    Py_DECREF(tp_name);
-
-    PyObject *HeapTypeNameType = PyType_FromSpec(&HeapTypeNameType_Spec);
-    if (HeapTypeNameType == NULL) {
-        Py_RETURN_NONE;
-    }
-    tp_name = PyType_GetName((PyTypeObject *)HeapTypeNameType);
-    assert(strcmp(PyUnicode_AsUTF8(tp_name), "HeapTypeNameType") == 0);
-    Py_DECREF(tp_name);
-
-    PyObject *name = PyUnicode_FromString("test_name");
-    if (name == NULL) {
-        goto done;
-    }
-    if (PyObject_SetAttrString(HeapTypeNameType, "__name__", name) < 0) {
-        Py_DECREF(name);
-        goto done;
-    }
-    tp_name = PyType_GetName((PyTypeObject *)HeapTypeNameType);
-    assert(strcmp(PyUnicode_AsUTF8(tp_name), "test_name") == 0);
-    Py_DECREF(name);
-    Py_DECREF(tp_name);
-
-  done:
-    Py_DECREF(HeapTypeNameType);
-    Py_RETURN_NONE;
+    assert(PyType_Check(type));
+    return PyType_GetName((PyTypeObject *)type);
 }
 
 
 static PyObject *
-test_get_type_qualname(PyObject *self, PyObject *Py_UNUSED(ignored))
+get_type_qualname(PyObject *self, PyObject *type)
 {
-    PyObject *tp_qualname = PyType_GetQualName(&PyLong_Type);
-    assert(strcmp(PyUnicode_AsUTF8(tp_qualname), "int") == 0);
-    Py_DECREF(tp_qualname);
-
-    tp_qualname = PyType_GetQualName(&PyODict_Type);
-    assert(strcmp(PyUnicode_AsUTF8(tp_qualname), "OrderedDict") == 0);
-    Py_DECREF(tp_qualname);
-
-    PyObject *HeapTypeNameType = PyType_FromSpec(&HeapTypeNameType_Spec);
-    if (HeapTypeNameType == NULL) {
-        Py_RETURN_NONE;
-    }
-    tp_qualname = PyType_GetQualName((PyTypeObject *)HeapTypeNameType);
-    assert(strcmp(PyUnicode_AsUTF8(tp_qualname), "HeapTypeNameType") == 0);
-    Py_DECREF(tp_qualname);
+    assert(PyType_Check(type));
+    return PyType_GetQualName((PyTypeObject *)type);
+}
 
-    PyObject *spec_name = PyUnicode_FromString(HeapTypeNameType_Spec.name);
-    if (spec_name == NULL) {
-        goto done;
-    }
-    if (PyObject_SetAttrString(HeapTypeNameType,
-                               "__qualname__", spec_name) < 0) {
-        Py_DECREF(spec_name);
-        goto done;
-    }
-    tp_qualname = PyType_GetQualName((PyTypeObject *)HeapTypeNameType);
-    assert(strcmp(PyUnicode_AsUTF8(tp_qualname),
-                  "_testcapi.HeapTypeNameType") == 0);
-    Py_DECREF(spec_name);
-    Py_DECREF(tp_qualname);
 
-  done:
-    Py_DECREF(HeapTypeNameType);
-    Py_RETURN_NONE;
+static PyObject *
+get_type_fullyqualname(PyObject *self, PyObject *type)
+{
+    assert(PyType_Check(type));
+    return PyType_GetFullyQualifiedName((PyTypeObject *)type);
 }
 
+
 static PyObject *
 test_get_type_dict(PyObject *self, PyObject *Py_UNUSED(ignored))
 {
@@ -3317,8 +3265,9 @@ static PyMethodDef TestMethods[] = {
     {"test_buildvalue_N",        test_buildvalue_N,              METH_NOARGS},
     {"test_get_statictype_slots", test_get_statictype_slots,     METH_NOARGS},
     {"get_heaptype_for_name",     get_heaptype_for_name,         METH_NOARGS},
-    {"test_get_type_name",        test_get_type_name,            METH_NOARGS},
-    {"test_get_type_qualname",    test_get_type_qualname,        METH_NOARGS},
+    {"get_type_name",            get_type_name,                  METH_O},
+    {"get_type_qualname",        get_type_qualname,              METH_O},
+    {"get_type_fullyqualname",   get_type_fullyqualname,         METH_O},
     {"test_get_type_dict",        test_get_type_dict,            METH_NOARGS},
     {"_test_thread_state",      test_thread_state,               METH_VARARGS},
 #ifndef MS_WINDOWS

Objects/typeobject.c

@@ -1201,6 +1201,52 @@ type_set_module(PyTypeObject *type, PyObject *value, void *context)
     return PyDict_SetItem(dict, &_Py_ID(__module__), value);
 }
 
+
+static PyObject*
+type_fullyqualname(PyTypeObject *type, int is_repr)
+{
+    // type is a static type and PyType_Ready() was not called on it yet?
+    if (type->tp_name == NULL) {
+        PyErr_SetString(PyExc_TypeError, "static type not initialized");
+        return NULL;
+    }
+
+    if (!(type->tp_flags & Py_TPFLAGS_HEAPTYPE)) {
+        return PyUnicode_FromString(type->tp_name);
+    }
+
+    PyObject *qualname = type_qualname(type, NULL);
+    if (qualname == NULL) {
+        return NULL;
+    }
+
+    PyObject *module = type_module(type, NULL);
+    if (module == NULL) {
+        if (is_repr) {
+            // type_repr() ignores type_module() errors
+            PyErr_Clear();
+            return qualname;
+        }
+
+        Py_DECREF(qualname);
+        return NULL;
+    }
+
+    PyObject *result;
+    if (PyUnicode_Check(module)
+        && !_PyUnicode_Equal(module, &_Py_ID(builtins)))
+    {
+        result = PyUnicode_FromFormat("%U.%U", module, qualname);
+    }
+    else {
+        result = Py_NewRef(qualname);
+    }
+    Py_DECREF(module);
+    Py_DECREF(qualname);
+    return result;
+}
+
+
 static PyObject *
 type_abstractmethods(PyTypeObject *type, void *context)
 {
@@ -1699,37 +1745,21 @@ static PyGetSetDef type_getsets[] = {
 };
 
 static PyObject *
-type_repr(PyObject *self)
+type_repr(PyTypeObject *type)
 {
-    PyTypeObject *type = (PyTypeObject *)self;
     if (type->tp_name == NULL) {
-        // type_repr() called before the type is fully initialized
-        // by PyType_Ready().
+        // If type_repr() is called before the type is fully initialized
+        // by PyType_Ready(), just format the type memory address.
         return PyUnicode_FromFormat("<class at %p>", type);
     }
 
-    PyObject *mod, *name, *rtn;
-
-    mod = type_module(type, NULL);
-    if (mod == NULL)
-        PyErr_Clear();
-    else if (!PyUnicode_Check(mod)) {
-        Py_SETREF(mod, NULL);
-    }
-    name = type_qualname(type, NULL);
+    PyObject *name = type_fullyqualname(type, 1);
     if (name == NULL) {
-        Py_XDECREF(mod);
         return NULL;
     }
-
-    if (mod != NULL && !_PyUnicode_Equal(mod, &_Py_ID(builtins)))
-        rtn = PyUnicode_FromFormat("<class '%U.%U'>", mod, name);
-    else
-        rtn = PyUnicode_FromFormat("<class '%s'>", type->tp_name);
-
-    Py_XDECREF(mod);
+    PyObject *result = PyUnicode_FromFormat("<class '%U'>", name);
     Py_DECREF(name);
-    return rtn;
+    return result;
 }
 
 static PyObject *
@@ -4701,6 +4731,13 @@ _PyType_GetModuleName(PyTypeObject *type)
     return type_module(type, NULL);
 }
 
+PyObject *
+PyType_GetFullyQualifiedName(PyTypeObject *type)
+{
+    return type_fullyqualname(type, 0);
+}
+
+
 void *
 PyType_GetSlot(PyTypeObject *type, int slot)
 {
@@ -5617,7 +5654,7 @@ PyTypeObject PyType_Type = {
     0,                                          /* tp_getattr */
     0,                                          /* tp_setattr */
     0,                                          /* tp_as_async */
-    type_repr,                                  /* tp_repr */
+    (reprfunc)type_repr,                        /* tp_repr */
     &type_as_number,                            /* tp_as_number */
     0,                                          /* tp_as_sequence */
     0,                                          /* tp_as_mapping */