Issue #25447: The lru_cache() wrapper objects now can be copied and pickled
(by returning the original object unchanged).
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index 7ecf877..d822b2d 100644
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -1,5 +1,6 @@
import abc
import collections
+import copy
from itertools import permutations
import pickle
from random import choice
@@ -1251,11 +1252,64 @@
self.assertEqual(b.f.cache_info(), X.f.cache_info())
self.assertEqual(c.f.cache_info(), X.f.cache_info())
-class TestLRUC(TestLRU, unittest.TestCase):
- module = c_functools
+ def test_pickle(self):
+ cls = self.__class__
+ for f in cls.cached_func[0], cls.cached_meth, cls.cached_staticmeth:
+ for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+ with self.subTest(proto=proto, func=f):
+ f_copy = pickle.loads(pickle.dumps(f, proto))
+ self.assertIs(f_copy, f)
+
+ def test_copy(self):
+ cls = self.__class__
+ for f in cls.cached_func[0], cls.cached_meth, cls.cached_staticmeth:
+ with self.subTest(func=f):
+ f_copy = copy.copy(f)
+ self.assertIs(f_copy, f)
+
+ def test_deepcopy(self):
+ cls = self.__class__
+ for f in cls.cached_func[0], cls.cached_meth, cls.cached_staticmeth:
+ with self.subTest(func=f):
+ f_copy = copy.deepcopy(f)
+ self.assertIs(f_copy, f)
+
+
+@py_functools.lru_cache()
+def py_cached_func(x, y):
+ return 3 * x + y
+
+@c_functools.lru_cache()
+def c_cached_func(x, y):
+ return 3 * x + y
+
class TestLRUPy(TestLRU, unittest.TestCase):
module = py_functools
+ cached_func = py_cached_func,
+
+ @module.lru_cache()
+ def cached_meth(self, x, y):
+ return 3 * x + y
+
+ @staticmethod
+ @module.lru_cache()
+ def cached_staticmeth(x, y):
+ return 3 * x + y
+
+
+class TestLRUC(TestLRU, unittest.TestCase):
+ module = c_functools
+ cached_func = c_cached_func,
+
+ @module.lru_cache()
+ def cached_meth(self, x, y):
+ return 3 * x + y
+
+ @staticmethod
+ @module.lru_cache()
+ def cached_staticmeth(x, y):
+ return 3 * x + y
class TestSingleDispatch(unittest.TestCase):
diff --git a/Misc/NEWS b/Misc/NEWS
index 30d5f5e..6a24291 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -45,6 +45,9 @@
Library
-------
+- Issue #25447: The lru_cache() wrapper objects now can be copied and pickled
+ (by returning the original object unchanged).
+
- Issue #25390: typing: Don't crash on Union[str, Pattern].
- Issue #25441: asyncio: Raise error from drain() when socket is closed.
diff --git a/Modules/_functoolsmodule.c b/Modules/_functoolsmodule.c
index 1f98067..fadc0a9 100644
--- a/Modules/_functoolsmodule.c
+++ b/Modules/_functoolsmodule.c
@@ -1047,6 +1047,12 @@
Py_RETURN_NONE;
}
+static PyObject *
+lru_cache_reduce(PyObject *self, PyObject *unused)
+{
+ return PyObject_GetAttrString(self, "__qualname__");
+}
+
static int
lru_cache_tp_traverse(lru_cache_object *self, visitproc visit, void *arg)
{
@@ -1097,6 +1103,7 @@
static PyMethodDef lru_cache_methods[] = {
{"cache_info", (PyCFunction)lru_cache_cache_info, METH_NOARGS},
{"cache_clear", (PyCFunction)lru_cache_cache_clear, METH_NOARGS},
+ {"__reduce__", (PyCFunction)lru_cache_reduce, METH_NOARGS},
{NULL}
};