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gh-133438: Fix the use of the terms "argument" and "parameter" in error messages for invalid function calls #135172

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gh-133438: Fix the use of the terms "argument" and "parameter" in error messages for invalid function calls #135172

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8 changes: 4 additions & 4 deletions Lib/inspect.py
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Original file line number Diff line number Diff line change
Expand Up @@ -1391,7 +1391,7 @@ def _missing_arguments(f_name, argnames, pos, values):
s = ", ".join(names) + tail
raise TypeError("%s() missing %i required %s argument%s: %s" %
(f_name, missing,
"positional" if pos else "keyword-only",
"positional" if pos else "keyword",
"" if missing == 1 else "s", s))

def _too_many(f_name, args, kwonly, varargs, defcount, given, values):
Expand All @@ -1408,7 +1408,7 @@ def _too_many(f_name, args, kwonly, varargs, defcount, given, values):
sig = str(len(args))
kwonly_sig = ""
if kwonly_given:
msg = " positional argument%s (and %d keyword-only argument%s)"
msg = " positional argument%s (and %d keyword argument%s)"
kwonly_sig = (msg % ("s" if given != 1 else "", kwonly_given,
"s" if kwonly_given != 1 else ""))
raise TypeError("%s() takes %s positional argument%s but %d%s %s given" %
Expand Down Expand Up @@ -3107,7 +3107,7 @@ def _bind(self, args, kwargs, *, partial=False):
elif param.name in kwargs:
if param.kind == _POSITIONAL_ONLY:
if param.default is _empty:
msg = f'missing a required positional-only argument: {param.name!r}'
msg = f'missing a required positional argument: {param.name!r}'
raise TypeError(msg)
# Raise a TypeError once we are sure there is no
# **kwargs param later.
Expand All @@ -3130,7 +3130,7 @@ def _bind(self, args, kwargs, *, partial=False):
break
else:
if param.kind == _KEYWORD_ONLY:
argtype = ' keyword-only'
argtype = ' keyword'
else:
argtype = ''
msg = 'missing a required{argtype} argument: {arg!r}'
Expand Down
12 changes: 6 additions & 6 deletions Lib/test/test_extcall.py
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Original file line number Diff line number Diff line change
Expand Up @@ -401,7 +401,7 @@
>>> s3(**md)
Traceback (most recent call last):
...
TypeError: s3() missing 1 required keyword-only argument: 'n'
TypeError: s3() missing 1 required keyword argument: 'n'

Another helper function

Expand Down Expand Up @@ -487,17 +487,17 @@
>>> f(1, kw=3)
Traceback (most recent call last):
...
TypeError: f() takes 0 positional arguments but 1 positional argument (and 1 keyword-only argument) were given
TypeError: f() takes 0 positional arguments but 1 positional argument (and 1 keyword argument) were given
>>> def f(*, kw, b): pass
>>> f(1, 2, 3, b=3, kw=3)
Traceback (most recent call last):
...
TypeError: f() takes 0 positional arguments but 3 positional arguments (and 2 keyword-only arguments) were given
TypeError: f() takes 0 positional arguments but 3 positional arguments (and 2 keyword arguments) were given
>>> def f(a, b=2, *, kw): pass
>>> f(2, 3, 4, kw=4)
Traceback (most recent call last):
...
TypeError: f() takes from 1 to 2 positional arguments but 3 positional arguments (and 1 keyword-only argument) were given
TypeError: f() takes from 1 to 2 positional arguments but 3 positional arguments (and 1 keyword argument) were given

Too few and missing arguments:

Expand Down Expand Up @@ -533,12 +533,12 @@
>>> f()
Traceback (most recent call last):
...
TypeError: f() missing 1 required keyword-only argument: 'w'
TypeError: f() missing 1 required keyword argument: 'w'
>>> def f(*, a, b, c, d, e): pass
>>> f()
Traceback (most recent call last):
...
TypeError: f() missing 5 required keyword-only arguments: 'a', 'b', 'c', 'd', and 'e'
TypeError: f() missing 5 required keyword arguments: 'a', 'b', 'c', 'd', and 'e'

"""

Expand Down
6 changes: 3 additions & 3 deletions Lib/test/test_inspect/test_inspect.py
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Expand Up @@ -2243,7 +2243,7 @@ def test_errors(self):
# kwonlydefaults and raises a wrong TypeError
def f5(*, a): pass
with self.assertRaisesRegex(TypeError,
'missing 1 required keyword-only'):
'missing 1 required keyword argument'):
inspect.getcallargs(f5)


Expand Down Expand Up @@ -5405,7 +5405,7 @@ def test(foo, *, bar):
self.call(test, 1, bar=2, spam='ham')

with self.assertRaisesRegex(TypeError,
"missing a required keyword-only "
"missing a required keyword "
"argument: 'bar'"):
self.call(test, 1)

Expand Down Expand Up @@ -5462,7 +5462,7 @@ def test(a_po, b_po, c_po=3, /, foo=42, *, bar=50, **kwargs):
self.assertEqual(self.call(test, 1, 2, c_po=4),
(1, 2, 3, 42, 50, {'c_po': 4}))

with self.assertRaisesRegex(TypeError, "missing a required positional-only argument: 'a_po'"):
with self.assertRaisesRegex(TypeError, "missing a required positional argument: 'a_po'"):
self.call(test, a_po=1, b_po=2)

def without_var_kwargs(c_po=3, d_po=4, /):
Expand Down
6 changes: 3 additions & 3 deletions Lib/test/test_positional_only_arg.py
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Original file line number Diff line number Diff line change
Expand Up @@ -166,9 +166,9 @@ def test_positional_only_and_kwonlyargs_invalid_calls(self):
def f(a, b, /, c, *, d, e):
pass
f(1, 2, 3, d=1, e=2) # does not raise
with self.assertRaisesRegex(TypeError, r"missing 1 required keyword-only argument: 'd'"):
with self.assertRaisesRegex(TypeError, r"missing 1 required keyword argument: 'd'"):
f(1, 2, 3, e=2)
with self.assertRaisesRegex(TypeError, r"missing 2 required keyword-only arguments: 'd' and 'e'"):
with self.assertRaisesRegex(TypeError, r"missing 2 required keyword arguments: 'd' and 'e'"):
f(1, 2, 3)
with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'c'"):
f(1, 2)
Expand All @@ -177,7 +177,7 @@ def f(a, b, /, c, *, d, e):
with self.assertRaisesRegex(TypeError, r" missing 3 required positional arguments: 'a', 'b', and 'c'"):
f()
with self.assertRaisesRegex(TypeError, r"f\(\) takes 3 positional arguments but 6 positional arguments "
r"\(and 2 keyword-only arguments\) were given"):
r"\(and 2 keyword arguments\) were given"):
f(1, 2, 3, 4, 5, 6, d=7, e=8)
with self.assertRaisesRegex(TypeError, r"f\(\) got an unexpected keyword argument 'f'"):
f(1, 2, 3, d=1, e=4, f=56)
Expand Down
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Core_and_Builtins/2025-06-05-12-51-52.gh-issue-133438.-3S9y4.rst
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@@ -0,0 +1,2 @@
Fix the use of the terms "argument" and "parameter" in error messages for
invalid function calls.
4 changes: 2 additions & 2 deletions Python/ceval.c
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Expand Up @@ -1318,7 +1318,7 @@ missing_arguments(PyThreadState *tstate, PyCodeObject *co,
Py_ssize_t i, j = 0;
Py_ssize_t start, end;
int positional = (defcount != -1);
const char *kind = positional ? "positional" : "keyword-only";
const char *kind = positional ? "positional" : "keyword";
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Why not keeping keyword-only here, it's correct, no?

>>> def f(*, x): pass
... 
>>> f()
Traceback (most recent call last):
  File "<python-input-1>", line 1, in <module>
    f()
    ~^^
TypeError: f() missing 1 required keyword-only argument: 'x'

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"Keyword-only" is a qualifier of a parameter. Arguments can be "positional" or "keyword".

PyObject *missing_names;

/* Compute the names of the arguments that are missing. */
Expand Down Expand Up @@ -1380,7 +1380,7 @@ too_many_positional(PyThreadState *tstate, PyCodeObject *co,
if (sig == NULL)
return;
if (kwonly_given) {
const char *format = " positional argument%s (and %zd keyword-only argument%s)";
const char *format = " positional argument%s (and %zd keyword argument%s)";
kwonly_sig = PyUnicode_FromFormat(format,
given != 1 ? "s" : "",
kwonly_given,
Expand Down
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