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

silently ignore keyword arguments.

Lib/test/test_operator.py

@@ -371,6 +371,9 @@ class OperatorTestCase(unittest.TestCase):
         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)
         f = operator.attrgetter(2)
@@ -414,6 +417,9 @@ class OperatorTestCase(unittest.TestCase):
         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)
 
@@ -456,6 +462,9 @@ class OperatorTestCase(unittest.TestCase):
         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

@@ -77,6 +77,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #26822: itemgetter, attrgetter and methodcaller objects no longer
+  silently ignore keyword arguments.
+
 - Issue #26657: Fix directory traversal vulnerability with SimpleHTTPServer
   on Windows.  This fixes a regression that was introduced in 2.7.7.  Based
   on patch by Philipp Hagemeister.

Modules/operator.c

@@ -511,6 +511,8 @@ 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)
@@ -691,6 +693,8 @@ 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)
@@ -838,6 +842,8 @@ 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);