Skip to content

gh-116436: Improve error message when TypeError occurs during dict update #116443

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 7 commits into from
Apr 30, 2025
Merged

gh-116436: Improve error message when TypeError occurs during dict update #116443

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
f07618a
gh-116436: Improve error message when TypeError occurs during dict up…
hauntsaninja Mar 6, 2024
0884054
📜🤖 Added by blurb_it.
blurb-it[bot] Mar 6, 2024
887608c
Merge branch 'main' into gh116436
hauntsaninja Apr 6, 2025
164e02e
.
hauntsaninja Apr 6, 2025
3ddeb3e
Merge branch 'main' into gh116436
hauntsaninja Apr 14, 2025
ec9980e
Merge branch 'main' into gh116436
hauntsaninja Apr 18, 2025
df92716
.
hauntsaninja Apr 19, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
25 changes: 25 additions & 0 deletions Lib/test/test_dict.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -265,6 +265,31 @@ def __next__(self):

self.assertRaises(ValueError, {}.update, [(1, 2, 3)])

def test_update_type_error(self):
with self.assertRaises(TypeError) as cm:
{}.update([object() for _ in range(3)])

self.assertEqual(str(cm.exception), "object is not iterable")
self.assertEqual(
cm.exception.__notes__,
['Cannot convert dictionary update sequence element #0 to a sequence'],
)

def badgen():
yield "key"
raise TypeError("oops")
yield "value"

with self.assertRaises(TypeError) as cm:
dict([badgen() for _ in range(3)])

self.assertEqual(str(cm.exception), "oops")
self.assertEqual(
cm.exception.__notes__,
['Cannot convert dictionary update sequence element #0 to a sequence'],
)


def test_fromkeys(self):
self.assertEqual(dict.fromkeys('abc'), {'a':None, 'b':None, 'c':None})
d = {}
Expand Down
1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Core_and_Builtins/2024-03-06-22-33-33.gh-issue-116436.y8Thkt.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Improve error message when :exc:`TypeError` occurs during :meth:`dict.update`
9 changes: 5 additions & 4 deletions Objects/dictobject.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3706,13 +3706,14 @@ merge_from_seq2_lock_held(PyObject *d, PyObject *seq2, int override)
}

/* Convert item to sequence, and verify length 2. */
fast = PySequence_Fast(item, "");
fast = PySequence_Fast(item, "object is not iterable");
Copy link
Contributor Author

@hauntsaninja hauntsaninja Mar 6, 2024 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Technically, I guess PyObject_GetIter has a different error message for the edge case where __iter__ exists but returns a non-iterator.

I think nicest thing would be to change PySequence_Fast so that if m is NULL it doesn't clobber the message

if (fast == NULL) {
if (PyErr_ExceptionMatches(PyExc_TypeError))
PyErr_Format(PyExc_TypeError,
"cannot convert dictionary update "
if (PyErr_ExceptionMatches(PyExc_TypeError)) {
_PyErr_FormatNote(
"Cannot convert dictionary update "
"sequence element #%zd to a sequence",
i);
}
goto Fail;
}
n = PySequence_Fast_GET_SIZE(fast);
Expand Down
Loading