Issue #26822: itemgetter, attrgetter and methodcaller objects no longer

silently ignore keyword arguments.

Lib/test/test_operator.py

@@ -318,6 +318,9 @@ class OperatorTestCase:
         a.name = 'arthur'
         f = operator.attrgetter('name')
         self.assertEqual(f(a), 'arthur')
+        self.assertRaises(TypeError, f)
+        self.assertRaises(TypeError, f, a, 'dent')
+        self.assertRaises(TypeError, f, a, surname='dent')
         f = operator.attrgetter('rank')
         self.assertRaises(AttributeError, f, a)
         self.assertRaises(TypeError, operator.attrgetter, 2)
@@ -365,6 +368,9 @@ class OperatorTestCase:
         a = 'ABCDE'
         f = operator.itemgetter(2)
         self.assertEqual(f(a), 'C')
+        self.assertRaises(TypeError, f)
+        self.assertRaises(TypeError, f, a, 3)
+        self.assertRaises(TypeError, f, a, size=3)
         f = operator.itemgetter(10)
         self.assertRaises(IndexError, f, a)
 
@@ -411,6 +417,9 @@ class OperatorTestCase:
         self.assertRaises(IndexError, f, a)
         f = operator.methodcaller('foo', 1, 2)
         self.assertEqual(f(a), 3)
+        self.assertRaises(TypeError, f)
+        self.assertRaises(TypeError, f, a, 3)
+        self.assertRaises(TypeError, f, a, spam=3)
         f = operator.methodcaller('bar')
         self.assertEqual(f(a), 42)
         self.assertRaises(TypeError, f, a, a)

Misc/NEWS

@@ -107,6 +107,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #26822: itemgetter, attrgetter and methodcaller objects no longer
+  silently ignore keyword arguments.
+
 - Issue #26733: Disassembling a class now disassembles class and static methods.
   Patch by Xiang Zhang.
 

Modules/_operator.c

@@ -460,6 +460,8 @@ itemgetter_call(itemgetterobject *ig, PyObject *args, PyObject *kw)
     PyObject *obj, *result;
     Py_ssize_t i, nitems=ig->nitems;
 
+    if (!_PyArg_NoKeywords("itemgetter", kw))
+        return NULL;
     if (!PyArg_UnpackTuple(args, "itemgetter", 1, 1, &obj))
         return NULL;
     if (nitems == 1)
@@ -747,6 +749,8 @@ attrgetter_call(attrgetterobject *ag, PyObject *args, PyObject *kw)
     PyObject *obj, *result;
     Py_ssize_t i, nattrs=ag->nattrs;
 
+    if (!_PyArg_NoKeywords("attrgetter", kw))
+        return NULL;
     if (!PyArg_UnpackTuple(args, "attrgetter", 1, 1, &obj))
         return NULL;
     if (ag->nattrs == 1) /* ag->attr is always a tuple */
@@ -988,6 +992,8 @@ methodcaller_call(methodcallerobject *mc, PyObject *args, PyObject *kw)
 {
     PyObject *method, *obj, *result;
 
+    if (!_PyArg_NoKeywords("methodcaller", kw))
+        return NULL;
     if (!PyArg_UnpackTuple(args, "methodcaller", 1, 1, &obj))
         return NULL;
     method = PyObject_GetAttr(obj, mc->name);