Fixed bug #1620: New @spam.getter property syntax modifies the property in place.
I added also the feature that a @prop.getter decorator does not overwrite the doc string of the property if it was given as an argument to property().
diff --git a/Lib/test/test_property.py b/Lib/test/test_property.py
new file mode 100644
index 0000000..4b6e20c
--- /dev/null
+++ b/Lib/test/test_property.py
@@ -0,0 +1,98 @@
+# Test case for property
+# more tests are in test_descr
+
+import unittest
+from test.test_support import run_unittest
+
+class PropertyBase(Exception):
+ pass
+
+class PropertyGet(PropertyBase):
+ pass
+
+class PropertySet(PropertyBase):
+ pass
+
+class PropertyDel(PropertyBase):
+ pass
+
+class BaseClass(object):
+ def __init__(self):
+ self._spam = 5
+
+ @property
+ def spam(self):
+ """BaseClass.getter"""
+ return self._spam
+
+ @spam.setter
+ def spam(self, value):
+ self._spam = value
+
+ @spam.deleter
+ def spam(self):
+ del self._spam
+
+class SubClass(BaseClass):
+
+ @BaseClass.spam.getter
+ def spam(self):
+ """SubClass.getter"""
+ raise PropertyGet(self._spam)
+
+ @spam.setter
+ def spam(self, value):
+ raise PropertySet(self._spam)
+
+ @spam.deleter
+ def spam(self):
+ raise PropertyDel(self._spam)
+
+class PropertyDocBase(object):
+ _spam = 1
+ def _get_spam(self):
+ return self._spam
+ spam = property(_get_spam, doc="spam spam spam")
+
+class PropertyDocSub(PropertyDocBase):
+ @PropertyDocBase.spam.getter
+ def spam(self):
+ """The decorator does not use this doc string"""
+ return self._spam
+
+class PropertyTests(unittest.TestCase):
+ def test_property_decorator_baseclass(self):
+ # see #1620
+ base = BaseClass()
+ self.assertEqual(base.spam, 5)
+ self.assertEqual(base._spam, 5)
+ base.spam = 10
+ self.assertEqual(base.spam, 10)
+ self.assertEqual(base._spam, 10)
+ delattr(base, "spam")
+ self.assert_(not hasattr(base, "spam"))
+ self.assert_(not hasattr(base, "_spam"))
+ base.spam = 20
+ self.assertEqual(base.spam, 20)
+ self.assertEqual(base._spam, 20)
+ self.assertEqual(base.__class__.spam.__doc__, "BaseClass.getter")
+
+ def test_property_decorator_subclass(self):
+ # see #1620
+ sub = SubClass()
+ self.assertRaises(PropertyGet, getattr, sub, "spam")
+ self.assertRaises(PropertySet, setattr, sub, "spam", None)
+ self.assertRaises(PropertyDel, delattr, sub, "spam")
+ self.assertEqual(sub.__class__.spam.__doc__, "SubClass.getter")
+
+ def test_property_decorator_doc(self):
+ base = PropertyDocBase()
+ sub = PropertyDocSub()
+ self.assertEqual(base.__class__.spam.__doc__, "spam spam spam")
+ self.assertEqual(sub.__class__.spam.__doc__, "spam spam spam")
+
+def test_main():
+ run_unittest(PropertyTests)
+
+if __name__ == '__main__':
+ test_main()
diff --git a/Misc/NEWS b/Misc/NEWS
index 0d420d0..3c95ca5 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
Core and builtins
-----------------
+- Issue #1620: New property decorator syntax was modifying the decorator
+ in place instead of creating a new decorator object.
+
- Issue #1580: New free format floating point representation based on
"Floating-Point Printer Sample Code", by Robert G. Burger. For example
repr(11./5) now returns '2.2' instead of '2.2000000000000002'.
diff --git a/Objects/descrobject.c b/Objects/descrobject.c
index 56599ef..3cfdb97 100644
--- a/Objects/descrobject.c
+++ b/Objects/descrobject.c
@@ -1098,8 +1098,12 @@
PyObject *prop_set;
PyObject *prop_del;
PyObject *prop_doc;
+ int getter_doc;
} propertyobject;
+static PyObject * property_copy(PyObject *, PyObject *, PyObject *,
+ PyObject *, PyObject *);
+
static PyMemberDef property_members[] = {
{"fget", T_OBJECT, offsetof(propertyobject, prop_get), READONLY},
{"fset", T_OBJECT, offsetof(propertyobject, prop_set), READONLY},
@@ -1108,53 +1112,37 @@
{0}
};
+
PyDoc_STRVAR(getter_doc,
"Descriptor to change the getter on a property.");
PyObject *
property_getter(PyObject *self, PyObject *getter)
{
- Py_XDECREF(((propertyobject *)self)->prop_get);
- if (getter == Py_None)
- getter = NULL;
- Py_XINCREF(getter);
- ((propertyobject *)self)->prop_get = getter;
- Py_INCREF(self);
- return self;
+ return property_copy(self, getter, NULL, NULL, NULL);
}
+
PyDoc_STRVAR(setter_doc,
- "Descriptor to change the setter on a property.\n");
+ "Descriptor to change the setter on a property.");
PyObject *
property_setter(PyObject *self, PyObject *setter)
{
- Py_XDECREF(((propertyobject *)self)->prop_set);
- if (setter == Py_None)
- setter = NULL;
- Py_XINCREF(setter);
- ((propertyobject *)self)->prop_set = setter;
- Py_INCREF(self);
- return self;
+ return property_copy(self, NULL, setter, NULL, NULL);
}
+
PyDoc_STRVAR(deleter_doc,
"Descriptor to change the deleter on a property.");
PyObject *
property_deleter(PyObject *self, PyObject *deleter)
{
- Py_XDECREF(((propertyobject *)self)->prop_del);
- if (deleter == Py_None)
- deleter = NULL;
- Py_XINCREF(deleter);
- ((propertyobject *)self)->prop_del = deleter;
- Py_INCREF(self);
- return self;
+ return property_copy(self, NULL, NULL, deleter, NULL);
}
-
static PyMethodDef property_methods[] = {
{"getter", property_getter, METH_O, getter_doc},
{"setter", property_setter, METH_O, setter_doc},
@@ -1219,15 +1207,62 @@
return 0;
}
+static PyObject *
+property_copy(PyObject *old, PyObject *get, PyObject *set, PyObject *del,
+ PyObject *doc)
+{
+ propertyobject *pold = (propertyobject *)old;
+ propertyobject *pnew = NULL;
+ PyObject *new, *type;
+
+ type = PyObject_Type(old);
+ if (type == NULL)
+ return NULL;
+
+ if (get == NULL || get == Py_None) {
+ Py_XDECREF(get);
+ get = pold->prop_get ? pold->prop_get : Py_None;
+ }
+ if (set == NULL || set == Py_None) {
+ Py_XDECREF(set);
+ set = pold->prop_set ? pold->prop_set : Py_None;
+ }
+ if (del == NULL || del == Py_None) {
+ Py_XDECREF(del);
+ del = pold->prop_del ? pold->prop_del : Py_None;
+ }
+ if (doc == NULL || doc == Py_None) {
+ Py_XDECREF(doc);
+ doc = pold->prop_doc ? pold->prop_doc : Py_None;
+ }
+
+ new = PyObject_CallFunction(type, "OOOO", get, set, del, doc);
+ if (new == NULL)
+ return NULL;
+ pnew = (propertyobject *)new;
+
+ if (pold->getter_doc && get != Py_None) {
+ PyObject *get_doc = PyObject_GetAttrString(get, "__doc__");
+ if (get_doc != NULL) {
+ Py_XDECREF(pnew->prop_doc);
+ pnew->prop_doc = get_doc; /* get_doc already INCREF'd by GetAttr */
+ pnew->getter_doc = 1;
+ } else {
+ PyErr_Clear();
+ }
+ }
+ return new;
+}
+
static int
property_init(PyObject *self, PyObject *args, PyObject *kwds)
{
PyObject *get = NULL, *set = NULL, *del = NULL, *doc = NULL;
static char *kwlist[] = {"fget", "fset", "fdel", "doc", 0};
- propertyobject *gs = (propertyobject *)self;
-
+ propertyobject *prop = (propertyobject *)self;
+
if (!PyArg_ParseTupleAndKeywords(args, kwds, "|OOOO:property",
- kwlist, &get, &set, &del, &doc))
+ kwlist, &get, &set, &del, &doc))
return -1;
if (get == Py_None)
@@ -1242,22 +1277,24 @@
Py_XINCREF(del);
Py_XINCREF(doc);
+ prop->prop_get = get;
+ prop->prop_set = set;
+ prop->prop_del = del;
+ prop->prop_doc = doc;
+ prop->getter_doc = 0;
+
/* if no docstring given and the getter has one, use that one */
if ((doc == NULL || doc == Py_None) && get != NULL) {
PyObject *get_doc = PyObject_GetAttrString(get, "__doc__");
if (get_doc != NULL) {
- Py_XDECREF(doc);
- doc = get_doc; /* get_doc already INCREF'd by GetAttr */
+ Py_XDECREF(prop->prop_doc);
+ prop->prop_doc = get_doc; /* get_doc already INCREF'd by GetAttr */
+ prop->getter_doc = 1;
} else {
PyErr_Clear();
}
}
- gs->prop_get = get;
- gs->prop_set = set;
- gs->prop_del = del;
- gs->prop_doc = doc;
-
return 0;
}