Minor bugs in the __index__ code (PEP 357), with tests.

Lib/test/test_index.py

@@ -10,9 +10,8 @@ class newstyle(object):
     def __index__(self):
         return self.ind
 
-class ListTestCase(unittest.TestCase):
+class BaseTestCase(unittest.TestCase):
     def setUp(self):
-        self.seq = [0,10,20,30,40,50]
         self.o = oldstyle()
         self.n = newstyle()
         self.o2 = oldstyle()
@@ -21,8 +20,8 @@ class ListTestCase(unittest.TestCase):
     def test_basic(self):
         self.o.ind = -2
         self.n.ind = 2
-        assert(self.seq[self.n] == 20)
-        assert(self.seq[self.o] == 40)
+        assert(self.seq[self.n] == self.seq[2])
+        assert(self.seq[self.o] == self.seq[-2])
         assert(operator.index(self.o) == -2)
         assert(operator.index(self.n) == 2)
 
@@ -43,108 +42,86 @@ class ListTestCase(unittest.TestCase):
         assert(self.seq[self.o:self.o2] == self.seq[1:3])
         assert(self.seq[self.n:self.n2] == self.seq[2:4])
 
-class TupleTestCase(unittest.TestCase):
-    def setUp(self):
-        self.seq = (0,10,20,30,40,50)
-        self.o = oldstyle()
-        self.n = newstyle()
-        self.o2 = oldstyle()
-        self.n2 = newstyle()
-
-
-    def test_basic(self):
+    def test_repeat(self):
+        self.o.ind = 3
+        self.n.ind = 2
+        assert(self.seq * self.o == self.seq * 3)
+        assert(self.seq * self.n == self.seq * 2)
+        assert(self.o * self.seq == self.seq * 3)
+        assert(self.n * self.seq == self.seq * 2)
+
+    def test_wrappers(self):
+        n = self.n
+        n.ind = 5
+        assert n.__index__() == 5
+        assert 6 .__index__() == 6
+        assert -7L.__index__() == -7
+        assert self.seq.__getitem__(n) == self.seq[5]
+        assert self.seq.__mul__(n) == self.seq * 5
+        assert self.seq.__rmul__(n) == self.seq * 5
+
+    def test_infinite_recusion(self):
+        class Trap1(int):
+            def __index__(self):
+                return self
+        class Trap2(long):
+            def __index__(self):
+                return self
+        self.failUnlessRaises(TypeError, operator.getitem, self.seq, Trap1())
+        self.failUnlessRaises(TypeError, operator.getitem, self.seq, Trap2())
+
+
+class ListTestCase(BaseTestCase):
+    seq = [0,10,20,30,40,50]
+
+    def test_setdelitem(self):
         self.o.ind = -2
         self.n.ind = 2
-        assert(self.seq[self.n] == 20)
-        assert(self.seq[self.o] == 40)
-        assert(operator.index(self.o) == -2)
-        assert(operator.index(self.n) == 2)
+        lst = list('ab!cdefghi!j')
+        del lst[self.o]
+        del lst[self.n]
+        lst[self.o] = 'X'
+        lst[self.n] = 'Y'
+        assert lst == list('abYdefghXj')
 
-    def test_error(self):
-        self.o.ind = 'dumb'
-        self.n.ind = 'bad'
-        myfunc = lambda x, obj: obj.seq[x]
-        self.failUnlessRaises(TypeError, operator.index, self.o)
-        self.failUnlessRaises(TypeError, operator.index, self.n)
-        self.failUnlessRaises(TypeError, myfunc, self.o, self)
-        self.failUnlessRaises(TypeError, myfunc, self.n, self)
+        lst = [5, 6, 7, 8, 9, 10, 11]
+        lst.__setitem__(self.n, "here")
+        assert lst == [5, 6, "here", 8, 9, 10, 11]
+        lst.__delitem__(self.n)
+        assert lst == [5, 6, 8, 9, 10, 11]
 
-    def test_slice(self):
-        self.o.ind = 1
-        self.o2.ind = 3
-        self.n.ind = 2
-        self.n2.ind = 4
-        assert(self.seq[self.o:self.o2] == self.seq[1:3])
-        assert(self.seq[self.n:self.n2] == self.seq[2:4])
+    def test_inplace_repeat(self):
+        self.o.ind = 2
+        self.n.ind = 3
+        lst = [6, 4]
+        lst *= self.o
+        assert lst == [6, 4, 6, 4]
+        lst *= self.n
+        assert lst == [6, 4, 6, 4] * 3
 
-class StringTestCase(unittest.TestCase):
-    def setUp(self):
-        self.seq = "this is a test"
-        self.o = oldstyle()
-        self.n = newstyle()
-        self.o2 = oldstyle()
-        self.n2 = newstyle()
+        lst = [5, 6, 7, 8, 9, 11]
+        l2 = lst.__imul__(self.n)
+        assert l2 is lst
+        assert lst == [5, 6, 7, 8, 9, 11] * 3
 
 
-    def test_basic(self):
-        self.o.ind = -2
-        self.n.ind = 2
-        assert(self.seq[self.n] == self.seq[2])
-        assert(self.seq[self.o] == self.seq[-2])
-        assert(operator.index(self.o) == -2)
-        assert(operator.index(self.n) == 2)
+class TupleTestCase(BaseTestCase):
+    seq = (0,10,20,30,40,50)
 
-    def test_error(self):
-        self.o.ind = 'dumb'
-        self.n.ind = 'bad'
-        myfunc = lambda x, obj: obj.seq[x]
-        self.failUnlessRaises(TypeError, operator.index, self.o)
-        self.failUnlessRaises(TypeError, operator.index, self.n)
-        self.failUnlessRaises(TypeError, myfunc, self.o, self)
-        self.failUnlessRaises(TypeError, myfunc, self.n, self)
+class StringTestCase(BaseTestCase):
+    seq = "this is a test"
 
-    def test_slice(self):
-        self.o.ind = 1
-        self.o2.ind = 3
-        self.n.ind = 2
-        self.n2.ind = 4
-        assert(self.seq[self.o:self.o2] == self.seq[1:3])
-        assert(self.seq[self.n:self.n2] == self.seq[2:4])
-
-
-class UnicodeTestCase(unittest.TestCase):
-    def setUp(self):
-        self.seq = u"this is a test"
-        self.o = oldstyle()
-        self.n = newstyle()
-        self.o2 = oldstyle()
-        self.n2 = newstyle()
+class UnicodeTestCase(BaseTestCase):
+    seq = u"this is a test"
 
 
-    def test_basic(self):
-        self.o.ind = -2
-        self.n.ind = 2
-        assert(self.seq[self.n] == self.seq[2])
-        assert(self.seq[self.o] == self.seq[-2])
-        assert(operator.index(self.o) == -2)
-        assert(operator.index(self.n) == 2)
-
-    def test_error(self):
-        self.o.ind = 'dumb'
-        self.n.ind = 'bad'
-        myfunc = lambda x, obj: obj.seq[x]
-        self.failUnlessRaises(TypeError, operator.index, self.o)
-        self.failUnlessRaises(TypeError, operator.index, self.n)
-        self.failUnlessRaises(TypeError, myfunc, self.o, self)
-        self.failUnlessRaises(TypeError, myfunc, self.n, self)
+class XRangeTestCase(unittest.TestCase):
 
-    def test_slice(self):
-        self.o.ind = 1
-        self.o2.ind = 3
-        self.n.ind = 2
-        self.n2.ind = 4
-        assert(self.seq[self.o:self.o2] == self.seq[1:3])
-        assert(self.seq[self.n:self.n2] == self.seq[2:4])
+    def test_xrange(self):
+        n = newstyle()
+        n.ind = 5
+        assert xrange(1, 20)[n] == 6
+        assert xrange(1, 20).__getitem__(n) == 6
 
 
 def test_main():
@@ -152,7 +129,8 @@ def test_main():
         ListTestCase,
         TupleTestCase,
         StringTestCase,
-        UnicodeTestCase
+        UnicodeTestCase,
+        XRangeTestCase,
     )
 
 if __name__ == "__main__":

Objects/abstract.c

@@ -942,8 +942,9 @@ PyNumber_Index(PyObject *item)
 		value = nb->nb_index(item);
 	}
 	else {
-		PyErr_SetString(PyExc_IndexError, 
-				"object cannot be interpreted as an index");
+		PyErr_Format(PyExc_TypeError,
+			     "'%.200s' object cannot be interpreted "
+			     "as an index", item->ob_type->tp_name);
 	}
 	return value;
 }

Objects/typeobject.c

@@ -3542,12 +3542,16 @@ wrap_unaryfunc(PyObject *self, PyObject *args, void *wrapped)
 }
 
 static PyObject *
-wrap_ssizeargfunc(PyObject *self, PyObject *args, void *wrapped)
+wrap_indexargfunc(PyObject *self, PyObject *args, void *wrapped)
 {
 	ssizeargfunc func = (ssizeargfunc)wrapped;
+	PyObject* o;
 	Py_ssize_t i;
 
-	if (!PyArg_ParseTuple(args, "n", &i))
+	if (!PyArg_UnpackTuple(args, "", 1, 1, &o))
+		return NULL;
+	i = PyNumber_Index(o);
+	if (i == -1 && PyErr_Occurred())
 		return NULL;
 	return (*func)(self, i);
 }
@@ -3557,7 +3561,7 @@ getindex(PyObject *self, PyObject *arg)
 {
 	Py_ssize_t i;
 
-	i = PyInt_AsSsize_t(arg);
+	i = PyNumber_Index(arg);
 	if (i == -1 && PyErr_Occurred())
 		return -1;
 	if (i < 0) {
@@ -4366,36 +4370,21 @@ slot_nb_nonzero(PyObject *self)
 static Py_ssize_t 
 slot_nb_index(PyObject *self)
 {
-	PyObject *func, *args;
 	static PyObject *index_str;
-	Py_ssize_t result = -1;
+	PyObject *temp = call_method(self, "__index__", &index_str, "()");
+	Py_ssize_t result;
 
-	func = lookup_maybe(self, "__index__", &index_str);
-	if (func == NULL) {
-		if (!PyErr_Occurred()) {
-			PyErr_SetString(PyExc_TypeError, 
-				"object cannot be interpreted as an index");
-		}
+	if (temp == NULL)
 		return -1;
- 	}
-	args = PyTuple_New(0);
-	if (args != NULL) {
-		PyObject *temp = PyObject_Call(func, args, NULL);
-		Py_DECREF(args);
-		if (temp != NULL) {
-			if (PyInt_Check(temp) || PyLong_Check(temp)) {
-				result =
-                                  temp->ob_type->tp_as_number->nb_index(temp);
-			}
-			else {
- 				PyErr_SetString(PyExc_TypeError, 
-				    "__index__ must return an int or a long");
-				result = -1;
-			}
-			Py_DECREF(temp);
-		}
+	if (PyInt_CheckExact(temp) || PyLong_CheckExact(temp)) {
+		result = temp->ob_type->tp_as_number->nb_index(temp);
 	}
-	Py_DECREF(func);
+	else {
+		PyErr_SetString(PyExc_TypeError, 
+				"__index__ must return an int or a long");
+		result = -1;
+	}
+	Py_DECREF(temp);
 	return result;
 }
 
@@ -5026,9 +5015,9 @@ static slotdef slotdefs[] = {
 	   test_descr.notimplemented() */
 	SQSLOT("__add__", sq_concat, NULL, wrap_binaryfunc,
           "x.__add__(y) <==> x+y"),
-	SQSLOT("__mul__", sq_repeat, NULL, wrap_ssizeargfunc,
+	SQSLOT("__mul__", sq_repeat, NULL, wrap_indexargfunc,
           "x.__mul__(n) <==> x*n"),
-	SQSLOT("__rmul__", sq_repeat, NULL, wrap_ssizeargfunc,
+	SQSLOT("__rmul__", sq_repeat, NULL, wrap_indexargfunc,
           "x.__rmul__(n) <==> n*x"),
 	SQSLOT("__getitem__", sq_item, slot_sq_item, wrap_sq_item,
 	       "x.__getitem__(y) <==> x[y]"),
@@ -5054,7 +5043,7 @@ static slotdef slotdefs[] = {
 	SQSLOT("__iadd__", sq_inplace_concat, NULL,
           wrap_binaryfunc, "x.__iadd__(y) <==> x+=y"),
 	SQSLOT("__imul__", sq_inplace_repeat, NULL,
-          wrap_ssizeargfunc, "x.__imul__(y) <==> x*=y"),
+          wrap_indexargfunc, "x.__imul__(y) <==> x*=y"),
 
 	MPSLOT("__len__", mp_length, slot_mp_length, wrap_lenfunc,
 	       "x.__len__() <==> len(x)"),