May 8, 2025 · Oct 9, 2024 · Oct 9, 2024 · Oct 17, 2024 · Oct 28, 2024 · Oct 28, 2024
diff --git a/Doc/library/functools.rst b/Doc/library/functools.rst
      >>> remove_first_dear(message)
      'Hello, dear world!'

   :data:`!Placeholder` has no special treatment when used in a keyword
   argument to :func:`!partial`.
   :data:`!Placeholder` cannot be passed to :func:`!partial` as a keyword argument.

   .. versionchanged:: 3.14
      Added support for :data:`Placeholder` in positional arguments.
diff --git a/Lib/functools.py b/Lib/functools.py
                            "or a descriptor")
    if args and args[-1] is Placeholder:
        raise TypeError("trailing Placeholders are not allowed")
    for value in keywords.values():
        if value is Placeholder:
            raise TypeError("Placeholder cannot be passed as a keyword argument")
    if isinstance(func, base_cls):
        pto_phcount = func._phcount
        tot_args = func.args
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
        actual_args, actual_kwds = p('x', 'y')
        self.assertEqual(actual_args, ('x', 0, 'y', 1))
        self.assertEqual(actual_kwds, {})
        # Checks via `is` and not `eq`
        # thus unittest.mock.ANY isn't treated as Placeholder
        p = self.partial(capture, unittest.mock.ANY)
        actual_args, actual_kwds = p()
        self.assertEqual(actual_args, (unittest.mock.ANY,))
        self.assertEqual(actual_kwds, {})

    def test_placeholders_optimization(self):
        PH = self.module.Placeholder
        self.assertEqual(p2.args, (PH, 0))
        self.assertEqual(p2(1), ((1, 0), {}))

    def test_placeholders_kw_restriction(self):
        PH = self.module.Placeholder
        with self.assertRaisesRegex(TypeError, "Placeholder"):
            self.partial(capture, a=PH)
        # Passes, as checks via `is` and not `eq`
        p = self.partial(capture, a=unittest.mock.ANY)
        actual_args, actual_kwds = p()
        self.assertEqual(actual_args, ())
        self.assertEqual(actual_kwds, {'a': unittest.mock.ANY})

    def test_construct_placeholder_singleton(self):
        PH = self.module.Placeholder
        tp = type(PH)
diff --git a/Misc/NEWS.d/next/Library/2024-10-28-06-54-22.gh-issue-125028.GEY8Ws.rst b/Misc/NEWS.d/next/Library/2024-10-28-06-54-22.gh-issue-125028.GEY8Ws.rst
 :data:`functools.Placeholder` cannot be passed to :func:`functools.partial` as a keyword argument.
diff --git a/Modules/_functoolsmodule.c b/Modules/_functoolsmodule.c
        return NULL;
    }

    /* keyword Placeholder prohibition */
    if (kw != NULL) {
        PyObject *key, *val;
        Py_ssize_t pos = 0;
        while (PyDict_Next(kw, &pos, &key, &val)) {
            if (val == phold) {
                PyErr_SetString(PyExc_TypeError,
                                "Placeholder cannot be passed as a keyword argument");
                return NULL;
            }
        }
    }

    /* check wrapped function / object */
    pto_args = pto_kw = NULL;
    int res = PyObject_TypeCheck(func, state->partial_type);
Original file line number	Diff line number	Diff line change
Expand Up		@@ -403,8 +403,7 @@ The :mod:`functools` module defines the following functions:
		>>> remove_first_dear(message)
		'Hello, dear world!'

		:data:`!Placeholder` has no special treatment when used in a keyword
		argument to :func:`!partial`.
		:data:`!Placeholder` cannot be passed to :func:`!partial` as a keyword argument.

		.. versionchanged:: 3.14
		Added support for :data:`Placeholder` in positional arguments.
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -326,6 +326,9 @@ def _partial_new(cls, func, /, args, *keywords):
		"or a descriptor")
		if args and args[-1] is Placeholder:
		raise TypeError("trailing Placeholders are not allowed")
		for value in keywords.values():
		if value is Placeholder:
		raise TypeError("Placeholder cannot be passed as a keyword argument")
		if isinstance(func, base_cls):
		pto_phcount = func._phcount
		tot_args = func.args
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -233,6 +233,12 @@ def test_placeholders(self):
		actual_args, actual_kwds = p('x', 'y')
		self.assertEqual(actual_args, ('x', 0, 'y', 1))
		self.assertEqual(actual_kwds, {})
		# Checks via `is` and not `eq`
		# thus unittest.mock.ANY isn't treated as Placeholder
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		p = self.partial(capture, unittest.mock.ANY)
		actual_args, actual_kwds = p()
		self.assertEqual(actual_args, (unittest.mock.ANY,))
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		self.assertEqual(actual_kwds, {})

		def test_placeholders_optimization(self):
		PH = self.module.Placeholder
Expand All		@@ -249,6 +255,16 @@ def test_placeholders_optimization(self):
		self.assertEqual(p2.args, (PH, 0))
		self.assertEqual(p2(1), ((1, 0), {}))

		def test_placeholders_kw_restriction(self):
		PH = self.module.Placeholder
		with self.assertRaisesRegex(TypeError, "Placeholder"):
		self.partial(capture, a=PH)
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		# Passes, as checks via `is` and not `eq`
		p = self.partial(capture, a=unittest.mock.ANY)
		actual_args, actual_kwds = p()
		self.assertEqual(actual_args, ())
		self.assertEqual(actual_kwds, {'a': unittest.mock.ANY})
dg-pb marked this conversation as resolved. Show resolvedHide resolved

		def test_construct_placeholder_singleton(self):
		PH = self.module.Placeholder
		tp = type(PH)
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		:data:`functools.Placeholder` cannot be passed to :func:`functools.partial` as a keyword argument.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -196,6 +196,19 @@ partial_new(PyTypeObject type, PyObject args, PyObject *kw)
		return NULL;
		}

		/* keyword Placeholder prohibition */
		if (kw != NULL) {
		PyObject key, val;
		Py_ssize_t pos = 0;
		while (PyDict_Next(kw, &pos, &key, &val)) {
		if (val == phold) {
		PyErr_SetString(PyExc_TypeError,
		"Placeholder cannot be passed as a keyword argument");
		return NULL;
		}
		}
		}

		/* check wrapped function / object */
		pto_args = pto_kw = NULL;
		int res = PyObject_TypeCheck(func, state->partial_type);
Expand Down