Reimplement PySequence_Contains() and instance_contains(), so they work
safely together and don't duplicate logic (the common logic was factored
out into new private API function _PySequence_IterContains()).
Visible change:
some_complex_number in some_instance
no longer blows up if some_instance has __getitem__ but neither
__contains__ nor __iter__. test_iter changed to ensure that remains true.
diff --git a/Include/abstract.h b/Include/abstract.h
index d5f4a99..9082edb 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -932,7 +932,17 @@
expression: o.count(value).
*/
- DL_IMPORT(int) PySequence_Contains(PyObject *o, PyObject *value);
+ DL_IMPORT(int) PySequence_Contains(PyObject *seq, PyObject *ob);
+ /*
+ Return -1 if error; 1 if ob in seq; 0 if ob not in seq.
+ Use __contains__ if possible, else _PySequence_IterContains().
+ */
+
+ DL_IMPORT(int) _PySequence_IterContains(PyObject *seq, PyObject *ob);
+ /*
+ Return -1 if error; 1 if ob in seq; 0 if ob not in seq.
+ Always uses the iteration protocol, and only Py_EQ comparisons.
+ */
/* For DLL-level backwards compatibility */
#undef PySequence_In
diff --git a/Lib/test/test_iter.py b/Lib/test/test_iter.py
index 7d15e1c..22a7c44 100644
--- a/Lib/test/test_iter.py
+++ b/Lib/test/test_iter.py
@@ -474,24 +474,12 @@
# Test iterators with 'x in y' and 'x not in y'.
def test_in_and_not_in(self):
- sc5 = IteratingSequenceClass(5)
- for i in range(5):
- self.assert_(i in sc5)
- # CAUTION: This test fails on 3-12j if sc5 is SequenceClass(5)
- # instead, with:
- # TypeError: cannot compare complex numbers using <, <=, >, >=
- # The trail leads back to instance_contains() in classobject.c,
- # under comment:
- # /* fall back to previous behavior */
- # IteratingSequenceClass(5) avoids the same problem only because
- # it lacks __getitem__: instance_contains *tries* to do a wrong
- # thing with it too, but aborts with an AttributeError the first
- # time it calls instance_item(); PySequence_Contains() then catches
- # that and clears it, and tries the iterator-based "contains"
- # instead. But this is hanging together by a thread.
- for i in "abc", -1, 5, 42.42, (3, 4), [], {1: 1}, 3-12j, sc5:
- self.assert_(i not in sc5)
- del sc5
+ for sc5 in IteratingSequenceClass(5), SequenceClass(5):
+ for i in range(5):
+ self.assert_(i in sc5)
+ for i in "abc", -1, 5, 42.42, (3, 4), [], {1: 1}, 3-12j, sc5:
+ self.assert_(i not in sc5)
+ del sc5
self.assertRaises(TypeError, lambda: 3 in 12)
self.assertRaises(TypeError, lambda: 3 not in map)
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 21c1ef1..c1d7789 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -1381,29 +1381,14 @@
return -1;
}
-/* Return -1 if error; 1 if v in w; 0 if v not in w. */
+/* Return -1 if error; 1 if ob in seq; 0 if ob not in seq.
+ * Always uses the iteration protocol, and only Py_EQ comparison.
+ */
int
-PySequence_Contains(PyObject *w, PyObject *v) /* v in w */
+_PySequence_IterContains(PyObject *seq, PyObject *ob)
{
- PyObject *it; /* iter(w) */
int result;
-
- if (PyType_HasFeature(w->ob_type, Py_TPFLAGS_HAVE_SEQUENCE_IN)) {
- PySequenceMethods *sq = w->ob_type->tp_as_sequence;
- if (sq != NULL && sq->sq_contains != NULL) {
- result = (*sq->sq_contains)(w, v);
- if (result >= 0)
- return result;
- assert(PyErr_Occurred());
- if (PyErr_ExceptionMatches(PyExc_AttributeError))
- PyErr_Clear();
- else
- return result;
- }
- }
-
- /* Try exhaustive iteration. */
- it = PyObject_GetIter(w);
+ PyObject *it = PyObject_GetIter(seq);
if (it == NULL) {
PyErr_SetString(PyExc_TypeError,
"'in' or 'not in' needs iterable right argument");
@@ -1417,7 +1402,7 @@
result = PyErr_Occurred() ? -1 : 0;
break;
}
- cmp = PyObject_RichCompareBool(v, item, Py_EQ);
+ cmp = PyObject_RichCompareBool(ob, item, Py_EQ);
Py_DECREF(item);
if (cmp == 0)
continue;
@@ -1428,6 +1413,20 @@
return result;
}
+/* Return -1 if error; 1 if ob in seq; 0 if ob not in seq.
+ * Use sq_contains if possible, else defer to _PySequence_IterContains().
+ */
+int
+PySequence_Contains(PyObject *seq, PyObject *ob)
+{
+ if (PyType_HasFeature(seq->ob_type, Py_TPFLAGS_HAVE_SEQUENCE_IN)) {
+ PySequenceMethods *sqm = seq->ob_type->tp_as_sequence;
+ if (sqm != NULL && sqm->sq_contains != NULL)
+ return (*sqm->sq_contains)(seq, ob);
+ }
+ return _PySequence_IterContains(seq, ob);
+}
+
/* Backwards compatibility */
#undef PySequence_In
int
diff --git a/Objects/classobject.c b/Objects/classobject.c
index 2babbfb..67732ca 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -1131,11 +1131,15 @@
return 0;
}
-static int instance_contains(PyInstanceObject *inst, PyObject *member)
+static int
+instance_contains(PyInstanceObject *inst, PyObject *member)
{
static PyObject *__contains__;
- PyObject *func, *arg, *res;
- int ret;
+ PyObject *func;
+
+ /* Try __contains__ first.
+ * If that can't be done, try iterator-based searching.
+ */
if(__contains__ == NULL) {
__contains__ = PyString_InternFromString("__contains__");
@@ -1143,45 +1147,34 @@
return -1;
}
func = instance_getattr(inst, __contains__);
- if(func == NULL) {
- /* fall back to previous behavior */
- int i, cmp_res;
-
- if(!PyErr_ExceptionMatches(PyExc_AttributeError))
+ if (func) {
+ PyObject *res;
+ int ret;
+ PyObject *arg = Py_BuildValue("(O)", member);
+ if(arg == NULL) {
+ Py_DECREF(func);
return -1;
- PyErr_Clear();
- for(i=0;;i++) {
- PyObject *obj = instance_item(inst, i);
- int ret = 0;
-
- if(obj == NULL) {
- if(!PyErr_ExceptionMatches(PyExc_IndexError))
- return -1;
- PyErr_Clear();
- return 0;
- }
- if(PyObject_Cmp(obj, member, &cmp_res) == -1)
- ret = -1;
- if(cmp_res == 0)
- ret = 1;
- Py_DECREF(obj);
- if(ret)
- return ret;
}
- }
- arg = Py_BuildValue("(O)", member);
- if(arg == NULL) {
+ res = PyEval_CallObject(func, arg);
Py_DECREF(func);
- return -1;
+ Py_DECREF(arg);
+ if(res == NULL)
+ return -1;
+ ret = PyObject_IsTrue(res);
+ Py_DECREF(res);
+ return ret;
}
- res = PyEval_CallObject(func, arg);
- Py_DECREF(func);
- Py_DECREF(arg);
- if(res == NULL)
+
+ /* Couldn't find __contains__. */
+ if (PyErr_ExceptionMatches(PyExc_AttributeError)) {
+ /* Assume the failure was simply due to that there is no
+ * __contains__ attribute, and try iterating instead.
+ */
+ PyErr_Clear();
+ return _PySequence_IterContains((PyObject *)inst, member);
+ }
+ else
return -1;
- ret = PyObject_IsTrue(res);
- Py_DECREF(res);
- return ret;
}
static PySequenceMethods