bpo-36144: Dictionary Union (PEP 584) (#12088)

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Brandt Bucher 2020-02-24 19:47:34 -08:00 committed by GitHub
parent ba22e8f174
commit eb8ac57af2
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4 changed files with 107 additions and 18 deletions

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@ -994,6 +994,26 @@ class UserDict(_collections_abc.MutableMapping):
# Now, add the methods in dicts but not in MutableMapping
def __repr__(self): return repr(self.data)
def __or__(self, other):
if isinstance(other, UserDict):
return self.__class__(self.data | other.data)
if isinstance(other, dict):
return self.__class__(self.data | other)
return NotImplemented
def __ror__(self, other):
if isinstance(other, UserDict):
return self.__class__(other.data | self.data)
if isinstance(other, dict):
return self.__class__(other | self.data)
return NotImplemented
def __ior__(self, other):
if isinstance(other, UserDict):
self.data |= other.data
else:
self.data |= other
return self
def __copy__(self):
inst = self.__class__.__new__(self.__class__)
inst.__dict__.update(self.__dict__)

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@ -37,6 +37,38 @@ class DictTest(unittest.TestCase):
dictliteral = '{' + ', '.join(formatted_items) + '}'
self.assertEqual(eval(dictliteral), dict(items))
def test_merge_operator(self):
a = {0: 0, 1: 1, 2: 1}
b = {1: 1, 2: 2, 3: 3}
c = a.copy()
c |= b
self.assertEqual(a | b, {0: 0, 1: 1, 2: 2, 3: 3})
self.assertEqual(c, {0: 0, 1: 1, 2: 2, 3: 3})
c = b.copy()
c |= a
self.assertEqual(b | a, {1: 1, 2: 1, 3: 3, 0: 0})
self.assertEqual(c, {1: 1, 2: 1, 3: 3, 0: 0})
c = a.copy()
c |= [(1, 1), (2, 2), (3, 3)]
self.assertEqual(c, {0: 0, 1: 1, 2: 2, 3: 3})
self.assertIs(a.__or__(None), NotImplemented)
self.assertIs(a.__or__(()), NotImplemented)
self.assertIs(a.__or__("BAD"), NotImplemented)
self.assertIs(a.__or__(""), NotImplemented)
self.assertRaises(TypeError, a.__ior__, None)
self.assertEqual(a.__ior__(()), {0: 0, 1: 1, 2: 1})
self.assertRaises(ValueError, a.__ior__, "BAD")
self.assertEqual(a.__ior__(""), {0: 0, 1: 1, 2: 1})
def test_bool(self):
self.assertIs(not {}, True)
self.assertTrue({1: 2})

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@ -0,0 +1,2 @@
:class:`dict` (and :class:`collections.UserDict`) objects now support PEP 584's merge (``|``) and update (``|=``) operators.
Patch by Brandt Bucher.

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@ -2320,6 +2320,25 @@ dict_fromkeys_impl(PyTypeObject *type, PyObject *iterable, PyObject *value)
return _PyDict_FromKeys((PyObject *)type, iterable, value);
}
/* Single-arg dict update; used by dict_update_common and operators. */
static int
dict_update_arg(PyObject *self, PyObject *arg)
{
if (PyDict_CheckExact(arg)) {
return PyDict_Merge(self, arg, 1);
}
_Py_IDENTIFIER(keys);
PyObject *func;
if (_PyObject_LookupAttrId(arg, &PyId_keys, &func) < 0) {
return -1;
}
if (func != NULL) {
Py_DECREF(func);
return PyDict_Merge(self, arg, 1);
}
return PyDict_MergeFromSeq2(self, arg, 1);
}
static int
dict_update_common(PyObject *self, PyObject *args, PyObject *kwds,
const char *methname)
@ -2331,23 +2350,7 @@ dict_update_common(PyObject *self, PyObject *args, PyObject *kwds,
result = -1;
}
else if (arg != NULL) {
if (PyDict_CheckExact(arg)) {
result = PyDict_Merge(self, arg, 1);
}
else {
_Py_IDENTIFIER(keys);
PyObject *func;
if (_PyObject_LookupAttrId(arg, &PyId_keys, &func) < 0) {
result = -1;
}
else if (func != NULL) {
Py_DECREF(func);
result = PyDict_Merge(self, arg, 1);
}
else {
result = PyDict_MergeFromSeq2(self, arg, 1);
}
}
result = dict_update_arg(self, arg);
}
if (result == 0 && kwds != NULL) {
@ -3169,6 +3172,33 @@ dict_sizeof(PyDictObject *mp, PyObject *Py_UNUSED(ignored))
return PyLong_FromSsize_t(_PyDict_SizeOf(mp));
}
static PyObject *
dict_or(PyObject *self, PyObject *other)
{
if (!PyDict_Check(self) || !PyDict_Check(other)) {
Py_RETURN_NOTIMPLEMENTED;
}
PyObject *new = PyDict_Copy(self);
if (new == NULL) {
return NULL;
}
if (dict_update_arg(new, other)) {
Py_DECREF(new);
return NULL;
}
return new;
}
static PyObject *
dict_ior(PyObject *self, PyObject *other)
{
if (dict_update_arg(self, other)) {
return NULL;
}
Py_INCREF(self);
return self;
}
PyDoc_STRVAR(getitem__doc__, "x.__getitem__(y) <==> x[y]");
PyDoc_STRVAR(sizeof__doc__,
@ -3274,6 +3304,11 @@ static PySequenceMethods dict_as_sequence = {
0, /* sq_inplace_repeat */
};
static PyNumberMethods dict_as_number = {
.nb_or = dict_or,
.nb_inplace_or = dict_ior,
};
static PyObject *
dict_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
@ -3335,7 +3370,7 @@ PyTypeObject PyDict_Type = {
0, /* tp_setattr */
0, /* tp_as_async */
(reprfunc)dict_repr, /* tp_repr */
0, /* tp_as_number */
&dict_as_number, /* tp_as_number */
&dict_as_sequence, /* tp_as_sequence */
&dict_as_mapping, /* tp_as_mapping */
PyObject_HashNotImplemented, /* tp_hash */