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gh-136327: Fix inconsistent TypeError messages regarding invalid values after * and ** #136395

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2 changes: 1 addition & 1 deletion Lib/test/pickletester.py
Original file line number Diff line number Diff line change
Expand Up @@ -1872,7 +1872,7 @@ def test_bad_newobj_ex_args(self):
with self.assertRaises(TypeError) as cm:
self.dumps(obj, proto)
self.assertEqual(str(cm.exception),
'functools.partial() argument after ** must be a mapping, not list')
'Value after ** must be a mapping, not list')
self.assertEqual(cm.exception.__notes__, [
'when serializing test.pickletester.REX object'])
else:
Expand Down
28 changes: 13 additions & 15 deletions Lib/test/test_extcall.py
Original file line number Diff line number Diff line change
Expand Up @@ -137,7 +137,7 @@
>>> g(*Nothing())
Traceback (most recent call last):
...
TypeError: test.test_extcall.g() argument after * must be an iterable, not Nothing
TypeError: Value after * must be an iterable, not Nothing

>>> class Nothing:
... def __len__(self): return 5
Expand All @@ -146,7 +146,7 @@
>>> g(*Nothing())
Traceback (most recent call last):
...
TypeError: test.test_extcall.g() argument after * must be an iterable, not Nothing
TypeError: Value after * must be an iterable, not Nothing

>>> class Nothing():
... def __len__(self): return 5
Expand Down Expand Up @@ -266,7 +266,7 @@
>>> h(*h)
Traceback (most recent call last):
...
TypeError: test.test_extcall.h() argument after * must be an iterable, not function
TypeError: Value after * must be an iterable, not function

>>> h(1, *h)
Traceback (most recent call last):
Expand All @@ -281,55 +281,53 @@
>>> dir(*h)
Traceback (most recent call last):
...
TypeError: dir() argument after * must be an iterable, not function
TypeError: Value after * must be an iterable, not function

>>> nothing = None
>>> nothing(*h)
Traceback (most recent call last):
...
TypeError: None argument after * must be an iterable, \
not function
TypeError: Value after * must be an iterable, not function

>>> h(**h)
Traceback (most recent call last):
...
TypeError: test.test_extcall.h() argument after ** must be a mapping, not function
TypeError: Value after ** must be a mapping, not function

>>> h(**[])
Traceback (most recent call last):
...
TypeError: test.test_extcall.h() argument after ** must be a mapping, not list
TypeError: Value after ** must be a mapping, not list

>>> h(a=1, **h)
Traceback (most recent call last):
...
TypeError: test.test_extcall.h() argument after ** must be a mapping, not function
TypeError: Value after ** must be a mapping, not function

>>> h(a=1, **[])
Traceback (most recent call last):
...
TypeError: test.test_extcall.h() argument after ** must be a mapping, not list
TypeError: Value after ** must be a mapping, not list

>>> h(**{'a': 1}, **h)
Traceback (most recent call last):
...
TypeError: test.test_extcall.h() argument after ** must be a mapping, not function
TypeError: Value after ** must be a mapping, not function

>>> h(**{'a': 1}, **[])
Traceback (most recent call last):
...
TypeError: test.test_extcall.h() argument after ** must be a mapping, not list
TypeError: Value after ** must be a mapping, not list

>>> dir(**h)
Traceback (most recent call last):
...
TypeError: dir() argument after ** must be a mapping, not function
TypeError: Value after ** must be a mapping, not function

>>> nothing(**h)
Traceback (most recent call last):
...
TypeError: None argument after ** must be a mapping, \
not function
TypeError: Value after ** must be a mapping, not function

>>> dir(b=1, **{'b': 1})
Traceback (most recent call last):
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Errors when calling functions with invalid values after * and ** now do not
include the function name.
27 changes: 7 additions & 20 deletions Python/ceval.c
Original file line number Diff line number Diff line change
Expand Up @@ -3264,17 +3264,9 @@ int
_Py_Check_ArgsIterable(PyThreadState *tstate, PyObject *func, PyObject *args)
{
if (Py_TYPE(args)->tp_iter == NULL && !PySequence_Check(args)) {
/* _Py_Check_ArgsIterable() may be called with a live exception:
* clear it to prevent calling _PyObject_FunctionStr() with an
* exception set. */
_PyErr_Clear(tstate);
PyObject *funcstr = _PyObject_FunctionStr(func);
if (funcstr != NULL) {
_PyErr_Format(tstate, PyExc_TypeError,
"%U argument after * must be an iterable, not %.200s",
funcstr, Py_TYPE(args)->tp_name);
Py_DECREF(funcstr);
}
_PyErr_Format(tstate, PyExc_TypeError,
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Why not to use %T formatter here? IIUC it is preferable now.

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Nikita's suggestions on removing the function name entirely were motivated by the fact that getting this name is not fast and does not add much value (in fact, none at all). I've looked into the %T specification, and it seems to do x2 of work we just got rid of, so I doubt that that would be a positive change. Anyway, we're waiting on Mark's review on that, maybe he has another opinion

"Value after * must be an iterable, not %.200s",
Py_TYPE(args)->tp_name);
return -1;
}
return 0;
Expand All @@ -3290,15 +3282,10 @@ _PyEval_FormatKwargsError(PyThreadState *tstate, PyObject *func, PyObject *kwarg
* is not a mapping.
*/
if (_PyErr_ExceptionMatches(tstate, PyExc_AttributeError)) {
_PyErr_Clear(tstate);
PyObject *funcstr = _PyObject_FunctionStr(func);
if (funcstr != NULL) {
_PyErr_Format(
tstate, PyExc_TypeError,
"%U argument after ** must be a mapping, not %.200s",
funcstr, Py_TYPE(kwargs)->tp_name);
Py_DECREF(funcstr);
}
_PyErr_Format(
tstate, PyExc_TypeError,
"Value after ** must be a mapping, not %.200s",
Py_TYPE(kwargs)->tp_name);
}
else if (_PyErr_ExceptionMatches(tstate, PyExc_KeyError)) {
PyObject *exc = _PyErr_GetRaisedException(tstate);
Expand Down
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