gh-118285: Fix signatures of operator.{attrgetter,itemgetter,methodcaller} instances (GH-118316)

* Allow to specify the signature of custom callable instances of extension
  type by the __text_signature__ attribute.
* Specify signatures of operator.attrgetter, operator.itemgetter, and
  operator.methodcaller instances.
This commit is contained in:
Serhiy Storchaka 2024-04-29 19:30:48 +03:00 committed by GitHub
parent 51c70de998
commit 444ac0b7a6
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
6 changed files with 76 additions and 5 deletions

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@ -2692,6 +2692,13 @@ def _signature_from_callable(obj, *,
# An object with __call__ # An object with __call__
call = getattr_static(type(obj), '__call__', None) call = getattr_static(type(obj), '__call__', None)
if call is not None: if call is not None:
try:
text_sig = obj.__text_signature__
except AttributeError:
pass
else:
if text_sig:
return _signature_fromstr(sigcls, obj, text_sig)
call = _descriptor_get(call, obj) call = _descriptor_get(call, obj)
return _get_signature_of(call) return _get_signature_of(call)

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@ -239,7 +239,7 @@ class attrgetter:
""" """
__slots__ = ('_attrs', '_call') __slots__ = ('_attrs', '_call')
def __init__(self, attr, *attrs): def __init__(self, attr, /, *attrs):
if not attrs: if not attrs:
if not isinstance(attr, str): if not isinstance(attr, str):
raise TypeError('attribute name must be a string') raise TypeError('attribute name must be a string')
@ -257,7 +257,7 @@ class attrgetter:
return tuple(getter(obj) for getter in getters) return tuple(getter(obj) for getter in getters)
self._call = func self._call = func
def __call__(self, obj): def __call__(self, obj, /):
return self._call(obj) return self._call(obj)
def __repr__(self): def __repr__(self):
@ -276,7 +276,7 @@ class itemgetter:
""" """
__slots__ = ('_items', '_call') __slots__ = ('_items', '_call')
def __init__(self, item, *items): def __init__(self, item, /, *items):
if not items: if not items:
self._items = (item,) self._items = (item,)
def func(obj): def func(obj):
@ -288,7 +288,7 @@ class itemgetter:
return tuple(obj[i] for i in items) return tuple(obj[i] for i in items)
self._call = func self._call = func
def __call__(self, obj): def __call__(self, obj, /):
return self._call(obj) return self._call(obj)
def __repr__(self): def __repr__(self):
@ -315,7 +315,7 @@ class methodcaller:
self._args = args self._args = args
self._kwargs = kwargs self._kwargs = kwargs
def __call__(self, obj): def __call__(self, obj, /):
return getattr(obj, self._name)(*self._args, **self._kwargs) return getattr(obj, self._name)(*self._args, **self._kwargs)
def __repr__(self): def __repr__(self):

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@ -4090,6 +4090,28 @@ class TestSignatureObject(unittest.TestCase):
((('a', ..., ..., "positional_or_keyword"),), ((('a', ..., ..., "positional_or_keyword"),),
...)) ...))
def test_signature_on_callable_objects_with_text_signature_attr(self):
class C:
__text_signature__ = '(a, /, b, c=True)'
def __call__(self, *args, **kwargs):
pass
self.assertEqual(self.signature(C), ((), ...))
self.assertEqual(self.signature(C()),
((('a', ..., ..., "positional_only"),
('b', ..., ..., "positional_or_keyword"),
('c', True, ..., "positional_or_keyword"),
),
...))
c = C()
c.__text_signature__ = '(x, y)'
self.assertEqual(self.signature(c),
((('x', ..., ..., "positional_or_keyword"),
('y', ..., ..., "positional_or_keyword"),
),
...))
def test_signature_on_wrapper(self): def test_signature_on_wrapper(self):
class Wrapper: class Wrapper:
def __call__(self, b): def __call__(self, b):

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@ -1,4 +1,5 @@
import unittest import unittest
import inspect
import pickle import pickle
import sys import sys
from decimal import Decimal from decimal import Decimal
@ -602,6 +603,28 @@ class OperatorTestCase:
if dunder: if dunder:
self.assertIs(dunder, orig) self.assertIs(dunder, orig)
def test_attrgetter_signature(self):
operator = self.module
sig = inspect.signature(operator.attrgetter)
self.assertEqual(str(sig), '(attr, /, *attrs)')
sig = inspect.signature(operator.attrgetter('x', 'z', 'y'))
self.assertEqual(str(sig), '(obj, /)')
def test_itemgetter_signature(self):
operator = self.module
sig = inspect.signature(operator.itemgetter)
self.assertEqual(str(sig), '(item, /, *items)')
sig = inspect.signature(operator.itemgetter(2, 3, 5))
self.assertEqual(str(sig), '(obj, /)')
def test_methodcaller_signature(self):
operator = self.module
sig = inspect.signature(operator.methodcaller)
self.assertEqual(str(sig), '(name, /, *args, **kwargs)')
sig = inspect.signature(operator.methodcaller('foo', 2, y=3))
self.assertEqual(str(sig), '(obj, /)')
class PyOperatorTestCase(OperatorTestCase, unittest.TestCase): class PyOperatorTestCase(OperatorTestCase, unittest.TestCase):
module = py_operator module = py_operator

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@ -0,0 +1,4 @@
Allow to specify the signature of custom callable instances of extension
type by the :attr:`__text_signature__` attribute. Specify signatures of
:class:`operator.attrgetter`, :class:`operator.itemgetter`, and
:class:`operator.methodcaller` instances.

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@ -966,6 +966,18 @@ static struct PyMethodDef operator_methods[] = {
}; };
static PyObject *
text_signature(PyObject *self, void *Py_UNUSED(ignored))
{
return PyUnicode_FromString("(obj, /)");
}
static PyGetSetDef common_getset[] = {
{"__text_signature__", text_signature, (setter)NULL},
{NULL}
};
/* itemgetter object **********************************************************/ /* itemgetter object **********************************************************/
typedef struct { typedef struct {
@ -1171,6 +1183,7 @@ static PyType_Slot itemgetter_type_slots[] = {
{Py_tp_clear, itemgetter_clear}, {Py_tp_clear, itemgetter_clear},
{Py_tp_methods, itemgetter_methods}, {Py_tp_methods, itemgetter_methods},
{Py_tp_members, itemgetter_members}, {Py_tp_members, itemgetter_members},
{Py_tp_getset, common_getset},
{Py_tp_new, itemgetter_new}, {Py_tp_new, itemgetter_new},
{Py_tp_getattro, PyObject_GenericGetAttr}, {Py_tp_getattro, PyObject_GenericGetAttr},
{Py_tp_repr, itemgetter_repr}, {Py_tp_repr, itemgetter_repr},
@ -1528,6 +1541,7 @@ static PyType_Slot attrgetter_type_slots[] = {
{Py_tp_clear, attrgetter_clear}, {Py_tp_clear, attrgetter_clear},
{Py_tp_methods, attrgetter_methods}, {Py_tp_methods, attrgetter_methods},
{Py_tp_members, attrgetter_members}, {Py_tp_members, attrgetter_members},
{Py_tp_getset, common_getset},
{Py_tp_new, attrgetter_new}, {Py_tp_new, attrgetter_new},
{Py_tp_getattro, PyObject_GenericGetAttr}, {Py_tp_getattro, PyObject_GenericGetAttr},
{Py_tp_repr, attrgetter_repr}, {Py_tp_repr, attrgetter_repr},
@ -1863,6 +1877,7 @@ static PyType_Slot methodcaller_type_slots[] = {
{Py_tp_clear, methodcaller_clear}, {Py_tp_clear, methodcaller_clear},
{Py_tp_methods, methodcaller_methods}, {Py_tp_methods, methodcaller_methods},
{Py_tp_members, methodcaller_members}, {Py_tp_members, methodcaller_members},
{Py_tp_getset, common_getset},
{Py_tp_new, methodcaller_new}, {Py_tp_new, methodcaller_new},
{Py_tp_getattro, PyObject_GenericGetAttr}, {Py_tp_getattro, PyObject_GenericGetAttr},
{Py_tp_repr, methodcaller_repr}, {Py_tp_repr, methodcaller_repr},