diff --git a/Objects/abstract.c b/Objects/abstract.c index 5ee53ee9f26..739d9d9d55e 100644 --- a/Objects/abstract.c +++ b/Objects/abstract.c @@ -1139,7 +1139,14 @@ PySequence_Contains(w, v) /* v in w */ } return 0; } - + if(PyType_HasFeature(w->ob_type, Py_TPFLAGS_HAVE_SEQUENCE_IN)) { + sq = w->ob_type->tp_as_sequence; + if(sq != NULL && sq->sq_contains != NULL) + return (*sq->sq_contains)(w, v); + } + + /* If there is no better way to check whether an item is is contained, + do it the hard way */ sq = w->ob_type->tp_as_sequence; if (sq == NULL || sq->sq_item == NULL) { PyErr_SetString(PyExc_TypeError,