python · RoryGlenn · Feb 15, 2026 · Feb 16, 2026 · Feb 24, 2026 · brijkapadia
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-02-15-02-51-59.gh-issue-140009.Da1nxk.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-02-15-02-51-59.gh-issue-140009.Da1nxk.rst
@@ -0,0 +1,3 @@
+Replace :c:func:`PyTuple_Pack` calls with :c:func:`PyTuple_FromArray` in
+:file:`Objects/codeobject.c` and :file:`Modules/_pickle.c` to avoid
+variadic argument overhead.
diff --git a/Modules/_pickle.c b/Modules/_pickle.c
@@ -3757,7 +3757,8 @@ fix_imports(PickleState *st, PyObject **module_name, PyObject **global_name)
    PyObject *key;
    PyObject *item;

-    key = PyTuple_Pack(2, *module_name, *global_name);
+    PyObject *key_items[] = {*module_name, *global_name};
+    key = PyTuple_FromArray(key_items, 2);
    if (key == NULL)
        return -1;
    item = PyDict_GetItemWithError(st->name_mapping_3to2, key);
@@ -3863,7 +3864,8 @@ save_global(PickleState *st, PicklerObject *self, PyObject *obj,
        char pdata[5];
        Py_ssize_t n;

-        extension_key = PyTuple_Pack(2, module_name, global_name);
+        PyObject *ext_key_items[] = {module_name, global_name};
+        extension_key = PyTuple_FromArray(ext_key_items, 2);
        if (extension_key == NULL) {
            goto error;
        }
@@ -7300,7 +7302,8 @@ _pickle_Unpickler_find_class_impl(UnpicklerObject *self, PyTypeObject *cls,

        /* Check if the global (i.e., a function or a class) was renamed
           or moved to another module. */
-        key = PyTuple_Pack(2, module_name, global_name);
+        PyObject *find_key_items[] = {module_name, global_name};
+        key = PyTuple_FromArray(find_key_items, 2);
        if (key == NULL)
            return NULL;
        item = PyDict_GetItemWithError(st->name_mapping_2to3, key);

@@ -3050,17 +3050,22 @@ _PyCode_ConstantKey(PyObject *op)
    else if (PyBool_Check(op) || PyBytes_CheckExact(op)) {
        /* Make booleans different from integers 0 and 1.
         * Avoid BytesWarning from comparing bytes with strings. */
-        key = PyTuple_Pack(2, Py_TYPE(op), op);
+        PyObject *items[] = {(PyObject *)Py_TYPE(op), op};
+        key = PyTuple_FromArray(items, 2);
    }
    else if (PyFloat_CheckExact(op)) {
        double d = PyFloat_AS_DOUBLE(op);
        /* all we need is to make the tuple different in either the 0.0
         * or -0.0 case from all others, just to avoid the "coercion".
         */
-        if (d == 0.0 && copysign(1.0, d) < 0.0)
-            key = PyTuple_Pack(3, Py_TYPE(op), op, Py_None);
-        else
-            key = PyTuple_Pack(2, Py_TYPE(op), op);
+        if (d == 0.0 && copysign(1.0, d) < 0.0) {
+            PyObject *items[] = {(PyObject *)Py_TYPE(op), op, Py_None};
+            key = PyTuple_FromArray(items, 3);
+        }
+        else {
+            PyObject *items[] = {(PyObject *)Py_TYPE(op), op};
+            key = PyTuple_FromArray(items, 2);
+        }
    }
    else if (PyComplex_CheckExact(op)) {
        Py_complex z;
@@ -3075,16 +3080,20 @@ _PyCode_ConstantKey(PyObject *op)
        /* use True, False and None singleton as tags for the real and imag
         * sign, to make tuples different */
        if (real_negzero && imag_negzero) {
-            key = PyTuple_Pack(3, Py_TYPE(op), op, Py_True);
+            PyObject *items[] = {(PyObject *)Py_TYPE(op), op, Py_True};
+            key = PyTuple_FromArray(items, 3);
        }
        else if (imag_negzero) {
-            key = PyTuple_Pack(3, Py_TYPE(op), op, Py_False);
+            PyObject *items[] = {(PyObject *)Py_TYPE(op), op, Py_False};
+            key = PyTuple_FromArray(items, 3);
        }
        else if (real_negzero) {
-            key = PyTuple_Pack(3, Py_TYPE(op), op, Py_None);
+            PyObject *items[] = {(PyObject *)Py_TYPE(op), op, Py_None};
+            key = PyTuple_FromArray(items, 3);
        }
        else {
-            key = PyTuple_Pack(2, Py_TYPE(op), op);
+            PyObject *items[] = {(PyObject *)Py_TYPE(op), op};
+            key = PyTuple_FromArray(items, 2);
        }
    }
    else if (PyTuple_CheckExact(op)) {
@@ -3109,7 +3118,8 @@ _PyCode_ConstantKey(PyObject *op)
            PyTuple_SET_ITEM(tuple, i, item_key);
        }

-        key = PyTuple_Pack(2, tuple, op);
+        PyObject *tuple_items[] = {tuple, op};
+        key = PyTuple_FromArray(tuple_items, 2);
        Py_DECREF(tuple);
    }
    else if (PyFrozenSet_CheckExact(op)) {
@@ -3143,7 +3153,8 @@ _PyCode_ConstantKey(PyObject *op)
        if (set == NULL)
            return NULL;

-        key = PyTuple_Pack(2, set, op);
+        PyObject *set_items[] = {set, op};
+        key = PyTuple_FromArray(set_items, 2);
        Py_DECREF(set);
        return key;
    }
@@ -3174,7 +3185,8 @@ _PyCode_ConstantKey(PyObject *op)
            goto slice_exit;
        }

-        key = PyTuple_Pack(2, slice_key, op);
+        PyObject *slice_items[] = {slice_key, op};
+        key = PyTuple_FromArray(slice_items, 2);
        Py_DECREF(slice_key);
    slice_exit:
        Py_XDECREF(start_key);
@@ -3188,7 +3200,8 @@ _PyCode_ConstantKey(PyObject *op)
        if (obj_id == NULL)
            return NULL;

-        key = PyTuple_Pack(2, obj_id, op);
+        PyObject *id_items[] = {obj_id, op};
+        key = PyTuple_FromArray(id_items, 2);
        Py_DECREF(obj_id);
    }
    return key;
-Original file line number
+Diff line change
@@ -0,0 +1,3 @@
+    Replace :c:func:`PyTuple_Pack` calls with :c:func:`PyTuple_FromArray` in
         Comment thread


        

        
      

        
          


  
    
        
        
  
    
      
          
      

      
            brijkapadia
  

      

      

      


        Feb 19, 2026



      
    

  

  
    
      
          
    
  


        
            
  
      
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      This is probably not necessary since nothing really changes from the user's perspective. Just mention that performance improved, similar to the NEWS entry for #140010
    
  
  



    

        
      
  
  
    
  
  
  
    
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+    :file:`Objects/codeobject.c` and :file:`Modules/_pickle.c` to avoid
+    variadic argument overhead.