gh-93741: Add private C API _PyImport_GetModuleAttrString() (GH-93742)

It combines PyImport_ImportModule() and PyObject_GetAttrString()
and saves 4-6 lines of code on every use.

Add also _PyImport_GetModuleAttr() which takes Python strings as arguments.

Author: serhiy-storchaka

Include/cpython/import.h

@@ -40,3 +40,6 @@ struct _frozen {
    collection of frozen modules: */
 
 PyAPI_DATA(const struct _frozen *) PyImport_FrozenModules;
+
+PyAPI_DATA(PyObject *) _PyImport_GetModuleAttr(PyObject *, PyObject *);
+PyAPI_DATA(PyObject *) _PyImport_GetModuleAttrString(const char *, const char *);

Include/internal/pycore_global_strings.h

@@ -226,7 +226,6 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(_showwarnmsg)
         STRUCT_FOR_ID(_shutdown)
         STRUCT_FOR_ID(_slotnames)
-        STRUCT_FOR_ID(_strptime_time)
         STRUCT_FOR_ID(_uninitialized_submodules)
         STRUCT_FOR_ID(_warn_unawaited_coroutine)
         STRUCT_FOR_ID(_xoptions)
@@ -252,7 +251,6 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(difference_update)
         STRUCT_FOR_ID(dispatch_table)
         STRUCT_FOR_ID(displayhook)
-        STRUCT_FOR_ID(enable)
         STRUCT_FOR_ID(encode)
         STRUCT_FOR_ID(encoding)
         STRUCT_FOR_ID(end_lineno)
@@ -311,7 +309,6 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(opcode)
         STRUCT_FOR_ID(open)
         STRUCT_FOR_ID(parent)
-        STRUCT_FOR_ID(partial)
         STRUCT_FOR_ID(path)
         STRUCT_FOR_ID(peek)
         STRUCT_FOR_ID(persistent_id)
@@ -357,7 +354,6 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(warnoptions)
         STRUCT_FOR_ID(writable)
         STRUCT_FOR_ID(write)
-        STRUCT_FOR_ID(zipimporter)
     } identifiers;
     struct {
         PyASCIIObject _ascii;

Include/internal/pycore_runtime_init.h

@@ -848,7 +848,6 @@ extern "C" {
                 INIT_ID(_showwarnmsg), \
                 INIT_ID(_shutdown), \
                 INIT_ID(_slotnames), \
-                INIT_ID(_strptime_time), \
                 INIT_ID(_uninitialized_submodules), \
                 INIT_ID(_warn_unawaited_coroutine), \
                 INIT_ID(_xoptions), \
@@ -874,7 +873,6 @@ extern "C" {
                 INIT_ID(difference_update), \
                 INIT_ID(dispatch_table), \
                 INIT_ID(displayhook), \
-                INIT_ID(enable), \
                 INIT_ID(encode), \
                 INIT_ID(encoding), \
                 INIT_ID(end_lineno), \
@@ -933,7 +931,6 @@ extern "C" {
                 INIT_ID(opcode), \
                 INIT_ID(open), \
                 INIT_ID(parent), \
-                INIT_ID(partial), \
                 INIT_ID(path), \
                 INIT_ID(peek), \
                 INIT_ID(persistent_id), \
@@ -979,7 +976,6 @@ extern "C" {
                 INIT_ID(warnoptions), \
                 INIT_ID(writable), \
                 INIT_ID(write), \
-                INIT_ID(zipimporter), \
             }, \
             .ascii = { \
                 _PyASCIIObject_INIT("\x00"), \

Modules/_ctypes/callbacks.c

@@ -472,24 +472,17 @@ static void LoadPython(void)
 
 long Call_GetClassObject(REFCLSID rclsid, REFIID riid, LPVOID *ppv)
 {
-    PyObject *mod, *func, *result;
+    PyObject *func, *result;
     long retval;
     static PyObject *context;
 
     if (context == NULL)
         context = PyUnicode_InternFromString("_ctypes.DllGetClassObject");
 
-    mod = PyImport_ImportModule("ctypes");
-    if (!mod) {
-        PyErr_WriteUnraisable(context ? context : Py_None);
-        /* There has been a warning before about this already */
-        return E_FAIL;
-    }
-
-    func = PyObject_GetAttrString(mod, "DllGetClassObject");
-    Py_DECREF(mod);
+    func = _PyImport_GetModuleAttrString("ctypes", "DllGetClassObject");
     if (!func) {
         PyErr_WriteUnraisable(context ? context : Py_None);
+        /* There has been a warning before about this already */
         return E_FAIL;
     }
 

Modules/_datetimemodule.c

@@ -1718,17 +1718,17 @@ wrap_strftime(PyObject *object, PyObject *format, PyObject *timetuple,
         goto Done;
     {
         PyObject *format;
-        PyObject *time = PyImport_ImportModule("time");
+        PyObject *strftime = _PyImport_GetModuleAttrString("time", "strftime");
 
-        if (time == NULL)
+        if (strftime == NULL)
             goto Done;
         format = PyUnicode_FromString(PyBytes_AS_STRING(newfmt));
         if (format != NULL) {
-            result = _PyObject_CallMethodIdObjArgs(time, &PyId_strftime,
+            result = PyObject_CallFunctionObjArgs(strftime,
                                                    format, timetuple, NULL);
             Py_DECREF(format);
         }
-        Py_DECREF(time);
+        Py_DECREF(strftime);
     }
  Done:
     Py_XDECREF(freplacement);
@@ -1748,12 +1748,10 @@ static PyObject *
 time_time(void)
 {
     PyObject *result = NULL;
-    PyObject *time = PyImport_ImportModule("time");
+    PyObject *time = _PyImport_GetModuleAttrString("time", "time");
 
     if (time != NULL) {
-        _Py_IDENTIFIER(time);
-
-        result = _PyObject_CallMethodIdNoArgs(time, &PyId_time);
+        result = PyObject_CallNoArgs(time);
         Py_DECREF(time);
     }
     return result;
@@ -1765,31 +1763,21 @@ time_time(void)
 static PyObject *
 build_struct_time(int y, int m, int d, int hh, int mm, int ss, int dstflag)
 {
-    PyObject *time;
+    PyObject *struct_time;
     PyObject *result;
-    _Py_IDENTIFIER(struct_time);
-    PyObject *args;
 
-
-    time = PyImport_ImportModule("time");
-    if (time == NULL) {
+    struct_time = _PyImport_GetModuleAttrString("time", "struct_time");
+    if (struct_time == NULL) {
         return NULL;
     }
 
-    args = Py_BuildValue("iiiiiiiii",
+    result = PyObject_CallFunction(struct_time, "((iiiiiiiii))",
                          y, m, d,
                          hh, mm, ss,
                          weekday(y, m, d),
                          days_before_month(y, m) + d,
                          dstflag);
-    if (args == NULL) {
-        Py_DECREF(time);
-        return NULL;
-    }
-
-    result = _PyObject_CallMethodIdOneArg(time, &PyId_struct_time, args);
-    Py_DECREF(time);
-    Py_DECREF(args);
+    Py_DECREF(struct_time);
     return result;
 }
 

Modules/_elementtree.c

@@ -4370,7 +4370,7 @@ static struct PyModuleDef elementtreemodule = {
 PyMODINIT_FUNC
 PyInit__elementtree(void)
 {
-    PyObject *m, *temp;
+    PyObject *m;
     elementtreestate *st;
 
     m = PyState_FindModule(&elementtreemodule);
@@ -4394,11 +4394,7 @@ PyInit__elementtree(void)
         return NULL;
     st = get_elementtree_state(m);
 
-    if (!(temp = PyImport_ImportModule("copy")))
-        return NULL;
-    st->deepcopy_obj = PyObject_GetAttrString(temp, "deepcopy");
-    Py_XDECREF(temp);
-
+    st->deepcopy_obj = _PyImport_GetModuleAttrString("copy", "deepcopy");
     if (st->deepcopy_obj == NULL) {
         return NULL;
     }

Modules/_operator.c

@@ -1752,16 +1752,11 @@ methodcaller_reduce(methodcallerobject *mc, PyObject *Py_UNUSED(ignored))
         return Py_BuildValue("ON", Py_TYPE(mc), newargs);
     }
     else {
-        PyObject *functools;
         PyObject *partial;
         PyObject *constructor;
         PyObject *newargs[2];
 
-        functools = PyImport_ImportModule("functools");
-        if (!functools)
-            return NULL;
-        partial = PyObject_GetAttr(functools, &_Py_ID(partial));
-        Py_DECREF(functools);
+        partial = _PyImport_GetModuleAttrString("functools", "partial");
         if (!partial)
             return NULL;
 

Modules/_pickle.c

@@ -232,8 +232,6 @@ _Pickle_InitState(PickleState *st)
 {
     PyObject *copyreg = NULL;
     PyObject *compat_pickle = NULL;
-    PyObject *codecs = NULL;
-    PyObject *functools = NULL;
 
     st->getattr = _PyEval_GetBuiltin(&_Py_ID(getattr));
     if (st->getattr == NULL)
@@ -329,10 +327,7 @@ _Pickle_InitState(PickleState *st)
     }
     Py_CLEAR(compat_pickle);
 
-    codecs = PyImport_ImportModule("codecs");
-    if (codecs == NULL)
-        goto error;
-    st->codecs_encode = PyObject_GetAttrString(codecs, "encode");
+    st->codecs_encode = _PyImport_GetModuleAttrString("codecs", "encode");
     if (st->codecs_encode == NULL) {
         goto error;
     }
@@ -342,23 +337,16 @@ _Pickle_InitState(PickleState *st)
                      Py_TYPE(st->codecs_encode)->tp_name);
         goto error;
     }
-    Py_CLEAR(codecs);
 
-    functools = PyImport_ImportModule("functools");
-    if (!functools)
-        goto error;
-    st->partial = PyObject_GetAttrString(functools, "partial");
+    st->partial = _PyImport_GetModuleAttrString("functools", "partial");
     if (!st->partial)
         goto error;
-    Py_CLEAR(functools);
 
     return 0;
 
   error:
     Py_CLEAR(copyreg);
     Py_CLEAR(compat_pickle);
-    Py_CLEAR(codecs);
-    Py_CLEAR(functools);
     _Pickle_ClearState(st);
     return -1;
 }

Modules/_sqlite/connection.c

@@ -1841,43 +1841,21 @@ static PyObject *
 pysqlite_connection_iterdump_impl(pysqlite_Connection *self)
 /*[clinic end generated code: output=586997aaf9808768 input=1911ca756066da89]*/
 {
-    PyObject* retval = NULL;
-    PyObject* module = NULL;
-    PyObject* module_dict;
-    PyObject* pyfn_iterdump;
-
     if (!pysqlite_check_connection(self)) {
-        goto finally;
-    }
-
-    module = PyImport_ImportModule(MODULE_NAME ".dump");
-    if (!module) {
-        goto finally;
-    }
-
-    module_dict = PyModule_GetDict(module);
-    if (!module_dict) {
-        goto finally;
+        return NULL;
     }
 
-    PyObject *meth = PyUnicode_InternFromString("_iterdump");
-    if (meth == NULL) {
-        goto finally;
-    }
-    pyfn_iterdump = PyDict_GetItemWithError(module_dict, meth);
-    Py_DECREF(meth);
-    if (!pyfn_iterdump) {
+    PyObject *iterdump = _PyImport_GetModuleAttrString(MODULE_NAME ".dump", "_iterdump");
+    if (!iterdump) {
         if (!PyErr_Occurred()) {
             PyErr_SetString(self->OperationalError,
                             "Failed to obtain _iterdump() reference");
         }
-        goto finally;
+        return NULL;
     }
 
-    retval = PyObject_CallOneArg(pyfn_iterdump, (PyObject *)self);
-
-finally:
-    Py_XDECREF(module);
+    PyObject *retval = PyObject_CallOneArg(iterdump, (PyObject *)self);
+    Py_DECREF(iterdump);
     return retval;
 }
 

Modules/_sqlite/module.c

@@ -227,14 +227,8 @@ static int converters_init(PyObject* module)
 static int
 load_functools_lru_cache(PyObject *module)
 {
-    PyObject *functools = PyImport_ImportModule("functools");
-    if (functools == NULL) {
-        return -1;
-    }
-
     pysqlite_state *state = pysqlite_get_state(module);
-    state->lru_cache = PyObject_GetAttrString(functools, "lru_cache");
-    Py_DECREF(functools);
+    state->lru_cache = _PyImport_GetModuleAttrString("functools", "lru_cache");
     if (state->lru_cache == NULL) {
         return -1;
     }