bpo-45482 Add PySimpleNamespace_New() function

Doc/c-api/concrete.rst

@@ -83,6 +83,7 @@ Container Objects
 
    dict.rst
    set.rst
+   simplenamespace.rst
 
 
 .. _otherobjects:

Doc/c-api/simplenamespace.rst

@@ -0,0 +1,15 @@
+.. highlight:: c
+
+SimpleNamespace Objects
+-----------------------
+
+.. c:function:: PyObject* PySimpleNamespace_New(PyObject *attrs)
+
+   Create a new simple namespace object.
+
+   *attrs* must be a mapping object with non-empty string keys.
+   It can be ``NULL``.
+
+   Return ``NULL`` and raise an exception on failure.
+
+   .. versionadded:: 3.11

Doc/whatsnew/3.11.rst

@@ -476,6 +476,10 @@ New Features
 * Add a new :c:func:`PyType_GetQualName` function to get type's qualified name.
   (Contributed by Hai Shi in :issue:`42035`.)
 
+* Add a new :c:func:`PySimpleNamespace_New` function to create a simple
+  namespace: C API of the :class:`types.SimpleNamespace` type.
+  (Contributed by Victor Stinner in :issue:`45482`.)
+
 Porting to Python 3.11
 ----------------------
 

Include/Python.h

@@ -76,7 +76,7 @@
 #include "warnings.h"
 #include "weakrefobject.h"
 #include "structseq.h"
-#include "namespaceobject.h"
+#include "cpython/namespaceobject.h"
 #include "cpython/picklebufobject.h"
 #include "cpython/pytime.h"
 #include "codecs.h"

Include/cpython/namespaceobject.h

@@ -0,0 +1,18 @@
+// Simple namespace object interface
+
+#ifndef Py_LIMITED_API
+#ifndef Py_NAMESPACEOBJECT_H
+#define Py_NAMESPACEOBJECT_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+PyAPI_DATA(PyTypeObject) _PySimpleNamespace_Type;
+
+PyAPI_FUNC(PyObject *) PySimpleNamespace_New(PyObject *attrs);
+
+#ifdef __cplusplus
+}
+#endif
+#endif  // !Py_NAMESPACEOBJECT_H
+#endif  // !Py_LIMITED_API

Lib/test/test_types.py

@@ -1,18 +1,20 @@
 # Python test set -- part 6, built-in types
 
-from test.support import run_with_locale, cpython_only
 import collections.abc
-from collections import namedtuple
 import copy
 import gc
 import inspect
-import pickle
 import locale
+import pickle
 import sys
 import types
+import typing
 import unittest.mock
 import weakref
-import typing
+
+from collections import namedtuple
+from test.support import run_with_locale, cpython_only
+from test.support import import_helper
 
 
 T = typing.TypeVar("T")
@@ -1733,6 +1735,45 @@ class FakeSimpleNamespace(str):
         with self.assertRaises(TypeError):
             types.SimpleNamespace() >= FakeSimpleNamespace()
 
+    def test_capi(self):
+        _testcapi = import_helper.import_module('_testcapi')
+        PySimpleNamespace_New = _testcapi.PySimpleNamespace_New
+
+        def list_attributes(obj):
+            return [name for name in dir(obj) if not name.startswith('_')]
+
+        # two attributes
+        value1 = 'value'
+        value2 = 2
+        ns = PySimpleNamespace_New({'attr1': value1, 'attr2': value2})
+        self.assertIsInstance(ns, types.SimpleNamespace)
+        self.assertEqual(list_attributes(ns), ['attr1', 'attr2'])
+        self.assertIs(ns.attr1, value1)
+        self.assertIs(ns.attr2, value2)
+
+        # it's possible to modify a namespace
+        ns.attr1 = 1
+        self.assertEqual(ns.attr1, 1)
+        ns.attr3 = 3
+        self.assertEqual(list_attributes(ns), ['attr1', 'attr2', 'attr3'])
+
+        # empty namespace
+        ns = PySimpleNamespace_New({})
+        self.assertIsInstance(ns, types.SimpleNamespace)
+        self.assertEqual(list_attributes(ns), [])
+
+        # invalid arguments
+        for invalid_arg in (
+            123,
+            'string',
+            [('key', 'value')],
+            # non-string key
+            {123: 'value'},
+        ):
+            with (self.subTest(invalid_arg=invalid_arg),
+                  self.assertRaises(TypeError)):
+                PySimpleNamespace_New(invalid_arg)
+
 
 class CoroutineTests(unittest.TestCase):
     def test_wrong_args(self):

Makefile.pre.in

@@ -1157,7 +1157,6 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/methodobject.h \
 		$(srcdir)/Include/modsupport.h \
 		$(srcdir)/Include/moduleobject.h \
-		$(srcdir)/Include/namespaceobject.h \
 		$(srcdir)/Include/object.h \
 		$(srcdir)/Include/objimpl.h \
 		$(srcdir)/Include/opcode.h \
@@ -1215,6 +1214,7 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/cpython/interpreteridobject.h \
 		$(srcdir)/Include/cpython/listobject.h \
 		$(srcdir)/Include/cpython/methodobject.h \
+		$(srcdir)/Include/cpython/namespaceobject.h \
 		$(srcdir)/Include/cpython/object.h \
 		$(srcdir)/Include/cpython/objimpl.h \
 		$(srcdir)/Include/cpython/odictobject.h \

Misc/NEWS.d/next/C API/2021-10-15-10-01-31.bpo-45482.69r5QI.rst

@@ -0,0 +1,3 @@
+Add a new :c:func:`PySimpleNamespace_New` function to create a simple
+namespace: C API of the :class:`types.SimpleNamespace` type. Patch by Victor
+Stinner.

Modules/_testcapimodule.c

@@ -1167,7 +1167,7 @@ test_get_type_qualname(PyObject *self, PyObject *Py_UNUSED(ignored))
     assert(strcmp(PyUnicode_AsUTF8(tp_qualname), "int") == 0);
     Py_DECREF(tp_qualname);
 
-    tp_qualname = PyType_GetQualName(&_PyNamespace_Type);
+    tp_qualname = PyType_GetQualName(&_PySimpleNamespace_Type);
     assert(strcmp(PyUnicode_AsUTF8(tp_qualname), "SimpleNamespace") == 0);
     Py_DECREF(tp_qualname);
 
@@ -5674,6 +5674,18 @@ type_get_version(PyObject *self, PyObject *type)
 }
 
 
+static PyObject *
+test_simplenamespace(PyObject *self, PyObject *args)
+{
+    PyObject *items = NULL;
+    if (!PyArg_ParseTuple(args, "|O", &items)) {
+        return NULL;
+    }
+
+    return PySimpleNamespace_New(items);
+}
+
+
 static PyObject *test_buildvalue_issue38913(PyObject *, PyObject *);
 static PyObject *getargs_s_hash_int(PyObject *, PyObject *, PyObject*);
 
@@ -5957,6 +5969,7 @@ static PyMethodDef TestMethods[] = {
     {"fatal_error", test_fatal_error, METH_VARARGS,
      PyDoc_STR("fatal_error(message, release_gil=False): call Py_FatalError(message)")},
     {"type_get_version", type_get_version, METH_O, PyDoc_STR("type->tp_version_tag")},
+    {"PySimpleNamespace_New", test_simplenamespace, METH_VARARGS, NULL},
     {NULL, NULL} /* sentinel */
 };
 

Modules/_testmultiphase.c

@@ -459,7 +459,7 @@ createfunc_nonmodule(PyObject *spec, PyModuleDef *def)
     PyDict_SetItemString(dct, "three", three);
     Py_DECREF(three);
 
-    ns = _PyNamespace_New(dct);
+    ns = PySimpleNamespace_New(dct);
     Py_DECREF(dct);
     return ns;
 }

Modules/timemodule.c

@@ -1653,7 +1653,7 @@ time_get_clock_info(PyObject *self, PyObject *args)
     }
     Py_CLEAR(obj);
 
-    ns = _PyNamespace_New(dict);
+    ns = PySimpleNamespace_New(dict);
     Py_DECREF(dict);
     return ns;
 

Objects/namespaceobject.c

@@ -72,8 +72,12 @@ namespace_repr(PyObject *ns)
     PyObject *separator, *pairsrepr, *repr = NULL;
     const char * name;
 
-    name = Py_IS_TYPE(ns, &_PyNamespace_Type) ? "namespace"
-                                               : Py_TYPE(ns)->tp_name;
+    if (Py_IS_TYPE(ns, &_PySimpleNamespace_Type)) {
+        name = "namespace";
+    }
+    else {
+        name = Py_TYPE(ns)->tp_name;
+    }
 
     i = Py_ReprEnter(ns);
     if (i != 0) {
@@ -163,8 +167,8 @@ namespace_clear(_PyNamespaceObject *ns)
 static PyObject *
 namespace_richcompare(PyObject *self, PyObject *other, int op)
 {
-    if (PyObject_TypeCheck(self, &_PyNamespace_Type) &&
-        PyObject_TypeCheck(other, &_PyNamespace_Type))
+    if (PyObject_TypeCheck(self, &_PySimpleNamespace_Type) &&
+        PyObject_TypeCheck(other, &_PySimpleNamespace_Type))
         return PyObject_RichCompare(((_PyNamespaceObject *)self)->ns_dict,
                                    ((_PyNamespaceObject *)other)->ns_dict, op);
     Py_RETURN_NOTIMPLEMENTED;
@@ -199,7 +203,7 @@ PyDoc_STRVAR(namespace_doc,
 \n\
 SimpleNamespace(**kwargs)");
 
-PyTypeObject _PyNamespace_Type = {
+PyTypeObject _PySimpleNamespace_Type = {
     PyVarObject_HEAD_INIT(&PyType_Type, 0)
     "types.SimpleNamespace",                    /* tp_name */
     sizeof(_PyNamespaceObject),                 /* tp_basicsize */
@@ -244,18 +248,32 @@ PyTypeObject _PyNamespace_Type = {
 
 
 PyObject *
-_PyNamespace_New(PyObject *kwds)
+PySimpleNamespace_New(PyObject *attrs)
 {
-    PyObject *ns = namespace_new(&_PyNamespace_Type, NULL, NULL);
-    if (ns == NULL)
+    if (attrs != NULL && !PyDict_Check(attrs)) {
+        PyErr_Format(PyExc_TypeError, "expected dict, got %s",
+                     Py_TYPE(attrs)->tp_name);
         return NULL;
+    }
 
-    if (kwds == NULL)
-        return ns;
-    if (PyDict_Update(((_PyNamespaceObject *)ns)->ns_dict, kwds) != 0) {
-        Py_DECREF(ns);
+    PyObject *ns = namespace_new(&_PySimpleNamespace_Type, NULL, NULL);
+    if (ns == NULL) {
         return NULL;
     }
 
-    return (PyObject *)ns;
+    if (attrs == NULL) {
+        return ns;
+    }
+
+    if (!PyArg_ValidateKeywordArguments(attrs)) {
+        goto error;
+    }
+    if (PyDict_Update(((_PyNamespaceObject *)ns)->ns_dict, attrs) < 0) {
+        goto error;
+    }
+    return ns;
+
+error:
+    Py_DECREF(ns);
+    return NULL;
 }

Objects/object.c

@@ -1947,7 +1947,7 @@ _PyTypes_Init(void)
     INIT_TYPE(_PyInterpreterID_Type);
     INIT_TYPE(_PyManagedBuffer_Type);
     INIT_TYPE(_PyMethodWrapper_Type);
-    INIT_TYPE(_PyNamespace_Type);
+    INIT_TYPE(_PySimpleNamespace_Type);
     INIT_TYPE(_PyNone_Type);
     INIT_TYPE(_PyNotImplemented_Type);
     INIT_TYPE(_PyWeakref_CallableProxyType);

PCbuild/pythoncore.vcxproj

@@ -140,6 +140,7 @@
     <ClInclude Include="..\Include\cpython\interpreteridobject.h" />
     <ClInclude Include="..\Include\cpython\listobject.h" />
     <ClInclude Include="..\Include\cpython\methodobject.h" />
+    <ClInclude Include="..\Include\cpython\namespaceobject.h" />
     <ClInclude Include="..\Include\cpython\object.h" />
     <ClInclude Include="..\Include\cpython\objimpl.h" />
     <ClInclude Include="..\Include\cpython\odictobject.h" />
@@ -231,7 +232,6 @@
     <ClInclude Include="..\Include\methodobject.h" />
     <ClInclude Include="..\Include\modsupport.h" />
     <ClInclude Include="..\Include\moduleobject.h" />
-    <ClInclude Include="..\Include\namespaceobject.h" />
     <ClInclude Include="..\Include\object.h" />
     <ClInclude Include="..\Include\objimpl.h" />
     <ClInclude Include="..\Include\opcode.h" />

PCbuild/pythoncore.vcxproj.filters

@@ -342,9 +342,6 @@
     <ClInclude Include="..\Include\pyhash.h">
       <Filter>Include</Filter>
     </ClInclude>
-    <ClInclude Include="..\Include\namespaceobject.h">
-      <Filter>Include</Filter>
-    </ClInclude>
     <ClInclude Include="..\Include\interpreteridobject.h">
       <Filter>Include</Filter>
     </ClInclude>
@@ -408,12 +405,15 @@
     <ClInclude Include="..\Include\cpython\methodobject.h">
       <Filter>Include\cpython</Filter>
     </ClInclude>
-    <ClInclude Include="..\Include\cpython\objimpl.h">
-      <Filter>Include\cpython</Filter>
+    <ClInclude Include="..\Include\cpython\namespaceobject.h">
+      <Filter>Include</Filter>
     </ClInclude>
     <ClInclude Include="..\Include\cpython\object.h">
       <Filter>Include\cpython</Filter>
     </ClInclude>
+    <ClInclude Include="..\Include\cpython\objimpl.h">
+      <Filter>Include\cpython</Filter>
+    </ClInclude>
     <ClInclude Include="..\Include\cpython\parser_interface.h">
       <Filter>Include</Filter>
     </ClInclude>

Python/import.c

@@ -2479,7 +2479,7 @@ _PyImport_BootstrapImp(PyThreadState *tstate)
     if (attrs == NULL) {
         goto error;
     }
-    PyObject *spec = _PyNamespace_New(attrs);
+    PyObject *spec = PySimpleNamespace_New(attrs);
     Py_DECREF(attrs);
     if (spec == NULL) {
         goto error;

Python/sysmodule.c

@@ -26,7 +26,7 @@ Data members:
 #include "pycore_pylifecycle.h"   // _PyErr_WriteUnraisableDefaultHook()
 #include "pycore_pymem.h"         // _PyMem_SetDefaultAllocator()
 #include "pycore_pystate.h"       // _PyThreadState_GET()
-#include "pycore_structseq.h"     // PyStructSequence_InitType()
+#include "pycore_structseq.h"     // _PyStructSequence_InitType()
 #include "pycore_tuple.h"         // _PyTuple_FromArray()
 
 #include "code.h"
@@ -2717,7 +2717,7 @@ make_impl_info(PyObject *version_info)
 
     /* dict ready */
 
-    ns = _PyNamespace_New(impl_info);
+    ns = PySimpleNamespace_New(impl_info);
     Py_DECREF(impl_info);
     return ns;