FIX pickle getset_descriptor (#290)

Author: pierreglaser

Diff for: CHANGES.md

@@ -4,6 +4,9 @@
 - Fix a bug affecting bound classmethod saving on Python 2.
   ([issue #288](https://github.com/cloudpipe/cloudpickle/issues/288))
 
+- Add support for pickling "getset" descriptors
+  ([issue #290](https://github.com/cloudpipe/cloudpickle/pull/290))
+
 1.2.1
 =====
 

Diff for: cloudpickle/cloudpickle.py

@@ -848,6 +848,11 @@ def save_builtin_function_or_method(self, obj):
         method_descriptor = type(str.upper)
         dispatch[method_descriptor] = save_builtin_function_or_method
 
+    def save_getset_descriptor(self, obj):
+        return self.save_reduce(getattr, (obj.__objclass__, obj.__name__))
+
+    dispatch[types.GetSetDescriptorType] = save_getset_descriptor
+
     def save_global(self, obj, name=None, pack=struct.pack):
         """
         Save a "global".

Diff for: cloudpickle/cloudpickle_fast.py

@@ -260,6 +260,10 @@ def _file_reduce(obj):
     return _file_reconstructor, (retval,)
 
 
+def _getset_descriptor_reduce(obj):
+    return getattr, (obj.__objclass__, obj.__name__)
+
+
 def _mappingproxy_reduce(obj):
     return types.MappingProxyType, (dict(obj),)
 
@@ -405,6 +409,7 @@ class CloudPickler(Pickler):
     dispatch[staticmethod] = _classmethod_reduce
     dispatch[types.CellType] = _cell_reduce
     dispatch[types.CodeType] = _code_reduce
+    dispatch[types.GetSetDescriptorType] = _getset_descriptor_reduce
     dispatch[types.ModuleType] = _module_reduce
     dispatch[types.MethodType] = _method_reduce
     dispatch[types.MappingProxyType] = _mappingproxy_reduce

Diff for: tests/cloudpickle_test.py

@@ -984,6 +984,11 @@ def test_logger(self):
         # logging.Logger object
         self.check_logger('cloudpickle.dummy_test_logger')
 
+    def test_getset_descriptor(self):
+        assert isinstance(float.real, types.GetSetDescriptorType)
+        depickled_descriptor = pickle_depickle(float.real)
+        self.assertIs(depickled_descriptor, float.real)
+
     def test_abc(self):
 
         @abc.abstractmethod