- When method objects have an attribute that can be satisfied either

by the function object or by the method object, the function
  object's attribute usually wins.  Christian Tismer pointed out that
  that this is really a mistake, because this only happens for special
  methods (like __reduce__) where the method object's version is
  really more appropriate than the function's attribute.  So from now
  on, all method attributes will have precedence over function
  attributes with the same name.
This commit is contained in:
Guido van Rossum 2003-11-22 23:55:50 +00:00
parent bfd334a42d
commit baf0f8f24d
2 changed files with 39 additions and 28 deletions

View File

@ -12,6 +12,15 @@ What's New in Python 2.4 alpha 1?
Core and builtins
-----------------
- When method objects have an attribute that can be satisfied either
by the function object or by the method object, the function
object's attribute usually wins. Christian Tismer pointed out that
that this is really a mistake, because this only happens for special
methods (like __reduce__) where the method object's version is
really more appropriate than the function's attribute. So from now
on, all method attributes will have precedence over function
attributes with the same name.
- Critical bugfix, for SF bug 839548: if a weakref with a callback,
its callback, and its weakly referenced object, all became part of
cyclic garbage during a single run of garbage collection, the order

View File

@ -2138,19 +2138,34 @@ static PyMemberDef instancemethod_memberlist[] = {
{NULL} /* Sentinel */
};
/* The getattr() implementation for PyMethod objects is similar to
PyObject_GenericGetAttr(), but instead of looking in __dict__ it
asks im_self for the attribute. Then the error handling is a bit
different because we want to preserve the exception raised by the
delegate, unless we have an alternative from our class. */
/* Christian Tismer argued convincingly that method attributes should
(nearly) always override function attributes.
The one exception is __doc__; there's a default __doc__ which
should only be used for the class, not for instances */
static PyObject *
instancemethod_get_doc(PyMethodObject *im, void *context)
{
static PyObject *docstr;
if (docstr == NULL) {
docstr= PyString_InternFromString("__doc__");
if (docstr == NULL)
return NULL;
}
return PyObject_GetAttr(im->im_func, docstr);
}
static PyGetSetDef instancemethod_getset[] = {
{"__doc__", (getter)instancemethod_get_doc, NULL, NULL},
{0}
};
static PyObject *
instancemethod_getattro(PyObject *obj, PyObject *name)
{
PyMethodObject *im = (PyMethodObject *)obj;
PyTypeObject *tp = obj->ob_type;
PyObject *descr = NULL, *res;
descrgetfunc f = NULL;
PyObject *descr = NULL;
if (PyType_HasFeature(tp, Py_TPFLAGS_HAVE_CLASS)) {
if (tp->tp_dict == NULL) {
@ -2160,30 +2175,17 @@ instancemethod_getattro(PyObject *obj, PyObject *name)
descr = _PyType_Lookup(tp, name);
}
f = NULL;
if (descr != NULL) {
f = TP_DESCR_GET(descr->ob_type);
if (f != NULL && PyDescr_IsData(descr))
descrgetfunc f = TP_DESCR_GET(descr->ob_type);
if (f != NULL)
return f(descr, obj, (PyObject *)obj->ob_type);
else {
Py_INCREF(descr);
return descr;
}
}
res = PyObject_GetAttr(im->im_func, name);
if (res != NULL || !PyErr_ExceptionMatches(PyExc_AttributeError))
return res;
if (f != NULL) {
PyErr_Clear();
return f(descr, obj, (PyObject *)obj->ob_type);
}
if (descr != NULL) {
PyErr_Clear();
Py_INCREF(descr);
return descr;
}
assert(PyErr_Occurred());
return NULL;
return PyObject_GetAttr(im->im_func, name);
}
PyDoc_STRVAR(instancemethod_doc,
@ -2490,7 +2492,7 @@ PyTypeObject PyMethod_Type = {
0, /* tp_iternext */
0, /* tp_methods */
instancemethod_memberlist, /* tp_members */
0, /* tp_getset */
instancemethod_getset, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
instancemethod_descr_get, /* tp_descr_get */