From 686b14d7ad700cfb3d3f0538695f0aa8e6c1b0b8 Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Wed, 7 May 2003 01:28:47 +0000 Subject: SF bug #730296: Unexpected Changes in list Iterator Reverted a Py2.3b1 change to iterator in subclasses of list and tuple. They had been changed to use __getitem__ whenever it had been overriden in the subclass. This caused some usabilty and performance problems. Also, it was inconsistent with the rest of python where many container methods access the underlying object directly without first checking for an overridden getter. Users needing a change in iterator behavior should override it directly. --- Lib/test/test_types.py | 8 ++++---- Misc/NEWS | 5 +++++ Objects/listobject.c | 2 -- Objects/tupleobject.c | 2 -- 4 files changed, 9 insertions(+), 8 deletions(-) diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py index 7e238df..1532295 100644 --- a/Lib/test/test_types.py +++ b/Lib/test/test_types.py @@ -256,11 +256,11 @@ def f(): yield i vereq(list(tuple(f())), range(1000)) -# Verify that __getitem__ overrides are recognized by __iter__ +# Verify that __getitem__ overrides are not recognized by __iter__ class T(tuple): def __getitem__(self, key): return str(key) + '!!!' -vereq(iter(T()).next(), '0!!!') +vereq(iter(T((1,2))).next(), 1) print '6.5.3 Lists' # calling built-in types without argument must return empty @@ -453,11 +453,11 @@ a = range(10) a[::2] = tuple(range(5)) vereq(a, [0, 1, 1, 3, 2, 5, 3, 7, 4, 9]) -# Verify that __getitem__ overrides are recognized by __iter__ +# Verify that __getitem__ overrides are not recognized by __iter__ class L(list): def __getitem__(self, key): return str(key) + '!!!' -vereq(iter(L()).next(), '0!!!') +vereq(iter(L([1,2])).next(), 1) print '6.6 Mappings == Dictionaries' diff --git a/Misc/NEWS b/Misc/NEWS index 9f982db..98feacc 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -15,6 +15,11 @@ Core and builtins - The softspace attribute of file objects became read-only by oversight. It's writable again. +- Reverted a 2.3 beta 1 change to iterators for subclasses of list and + tuple. By default, the iterators now access data elements directly + instead of going through __getitem__. If __getitem__ access is + preferred, then __iter__ can be overriden. + Extension modules ----------------- diff --git a/Objects/listobject.c b/Objects/listobject.c index 36bbe22..48f3d7d 100644 --- a/Objects/listobject.c +++ b/Objects/listobject.c @@ -2382,8 +2382,6 @@ list_iter(PyObject *seq) PyErr_BadInternalCall(); return NULL; } - if (seq->ob_type->tp_as_sequence->sq_item != (intargfunc)list_item) - return PySeqIter_New(seq); it = PyObject_GC_New(listiterobject, &PyListIter_Type); if (it == NULL) return NULL; diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c index 7456533..282da3e 100644 --- a/Objects/tupleobject.c +++ b/Objects/tupleobject.c @@ -753,8 +753,6 @@ tuple_iter(PyObject *seq) PyErr_BadInternalCall(); return NULL; } - if (seq->ob_type->tp_as_sequence->sq_item != (intargfunc)tupleitem) - return PySeqIter_New(seq); it = PyObject_GC_New(tupleiterobject, &PyTupleIter_Type); if (it == NULL) return NULL; -- cgit v0.12