Fix Python 3.9+ NamedTuple issues (#495)

Co-authored-by: Olivier Grisel <[email protected]>

Author: RyanClark2k

CHANGES.md

@@ -1,7 +1,8 @@
-2.3.0 (in development)
-======================
+2.2.1
+=====
 
-- TODO
+- Fix pickling of NamedTuple in Python 3.9+.
+  ([issue #460](https://github.com/cloudpipe/cloudpickle/issues/460))
 
 2.2.0
 =====

cloudpickle/cloudpickle_fast.py

@@ -111,8 +111,8 @@ def dumps(obj, protocol=None):
 
 def _class_getnewargs(obj):
     type_kwargs = {}
-    if "__slots__" in obj.__dict__:
-        type_kwargs["__slots__"] = obj.__slots__
+    if "__module__" in obj.__dict__:
+        type_kwargs["__module__"] = obj.__module__
 
     __dict__ = obj.__dict__.get('__dict__', None)
     if isinstance(__dict__, property):

tests/cloudpickle_test.py

@@ -1597,6 +1597,24 @@ def test_namedtuple(self):
         assert isinstance(depickled_t2, MyTuple)
         assert depickled_t2 == t2
 
+    def test_NamedTuple(self):
+        class MyTuple(typing.NamedTuple):
+            a: int
+            b: int
+            c: int
+
+        t1 = MyTuple(1, 2, 3)
+        t2 = MyTuple(3, 2, 1)
+
+        depickled_t1, depickled_MyTuple, depickled_t2 = pickle_depickle(
+            [t1, MyTuple, t2], protocol=self.protocol)
+
+        assert isinstance(depickled_t1, MyTuple)
+        assert depickled_t1 == t1
+        assert depickled_MyTuple is MyTuple
+        assert isinstance(depickled_t2, MyTuple)
+        assert depickled_t2 == t2
+
     def test_interactively_defined_function(self):
         # Check that callables defined in the __main__ module of a Python
         # script (or jupyter kernel) can be pickled / unpickled / executed.
@@ -2096,6 +2114,8 @@ def __init__(self):
             depickled_obj = pickle_depickle(
                 initial_obj, protocol=self.protocol)
 
+            assert depickled_obj.__class__.__slots__ == slots
+
             for obj in [initial_obj, depickled_obj]:
                 self.assertEqual(obj.registered_attribute, 42)
                 with pytest.raises(AttributeError):