mirrors/cpython
0
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2024-11-23 18:04:37 +08:00
Code Issues Packages Projects Releases Wiki Activity

gh-96663: Add a better error message for __dict__-less classes setattr (#103232)

Browse Source
This commit is contained in:
James Hilton-Balfe 2023-07-22 01:24:26 +01:00 committed by GitHub
parent 41ca164551
commit cdeb1a6caa
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
4 changed files with 32 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
Lib/test/test_class.py
View File

@ -641,6 +641,14 @@ class ClassTests(unittest.TestCase):
class B:
y = 0
__slots__ = ('z',)
class C:
__slots__ = ("y",)
def __setattr__(self, name, value) -> None:
if name == "z":
super().__setattr__("y", 1)
else:
super().__setattr__(name, value)
error_msg = "'A' object has no attribute 'x'"
with self.assertRaisesRegex(AttributeError, error_msg):
@ -653,8 +661,16 @@ class ClassTests(unittest.TestCase):
B().x
with self.assertRaisesRegex(AttributeError, error_msg):
del B().x
with self.assertRaisesRegex(AttributeError, error_msg):
with self.assertRaisesRegex(
AttributeError,
"'B' object has no attribute 'x' and no __dict__ for setting new attributes"
):
B().x = 0
with self.assertRaisesRegex(
AttributeError,
"'C' object has no attribute 'x'"
):
C().x = 0
error_msg = "'B' object attribute 'y' is read-only"
with self.assertRaisesRegex(AttributeError, error_msg):

2
Lib/test/test_descrtut.py
View File

@ -139,7 +139,7 @@ instance variables cannot be assigned to:
>>> a.x1 = 1
Traceback (most recent call last):
File "<stdin>", line 1, in ?
AttributeError: 'defaultdict2' object has no attribute 'x1'
AttributeError: 'defaultdict2' object has no attribute 'x1' and no __dict__ for setting new attributes
>>>
"""

1
Misc/NEWS.d/next/Core and Builtins/2023-04-04-00-40-04.gh-issue-96663.PdR9hK.rst Normal file
View File

@ -0,0 +1 @@
Add a better, more introspect-able error message when setting attributes on classes without a ``__dict__`` and no slot member for the attribute.

16
Objects/object.c
View File

@ -1576,9 +1576,18 @@ _PyObject_GenericSetAttrWithDict(PyObject *obj, PyObject *name,
}
if (dictptr == NULL) {
if (descr == NULL) {
PyErr_Format(PyExc_AttributeError,
"'%.100s' object has no attribute '%U'",
tp->tp_name, name);
if (tp->tp_setattro == PyObject_GenericSetAttr) {
PyErr_Format(PyExc_AttributeError,
"'%.100s' object has no attribute '%U' and no "
"__dict__ for setting new attributes",
tp->tp_name, name);
}
else {
PyErr_Format(PyExc_AttributeError,
"'%.100s' object has no attribute '%U'",
tp->tp_name, name);
}
set_attribute_error_context(obj, name);
}
else {
PyErr_Format(PyExc_AttributeError,
@ -1611,6 +1620,7 @@ _PyObject_GenericSetAttrWithDict(PyObject *obj, PyObject *name,
"'%.100s' object has no attribute '%U'",
tp->tp_name, name);
}
set_attribute_error_context(obj, name);
}
done:
Py_XDECREF(descr);