delete the function of saving layer object. (#33697)

* delete the function of saving layer object.

* edit doc of paddle.save/load and polish error message

python/paddle/fluid/framework.py

@@ -5578,18 +5578,6 @@ class ParamBase(core.VarBase):
         core.varbase_copy(self, new_param, device, blocking)
         return new_param
 
-    def __reduce__(self):
-        value = self.numpy()
-        state = (self.name, self.persistable, self.stop_gradient)
-        return ParamBase, (self.shape, self.dtype), (self.__dict__, value,
-                                                     state)
-
-    def __setstate__(self, state):
-        self.__dict__.update(state[0])
-        t = self.value().get_tensor()
-        t.set(state[1], _current_expected_place())
-        self.name, self.persistable, self.stop_gradient = state[2]
-
     __repr__ = __str__
 
 

python/paddle/fluid/tests/unittests/test_paddle_save_load.py

@@ -928,15 +928,9 @@ class TestSaveLoadLayer(unittest.TestCase):
         origin_layer = (layer1, layer2)
         origin = (layer1(inps), layer2(inps))
         path = "test_save_load_layer_/layer.pdmodel"
+        with self.assertRaises(ValueError):
             paddle.save(origin_layer, path)
 
-        loaded_layer = paddle.load(path)
-        loaded_result = [l(inps) for l in loaded_layer]
-        for i in range(len(origin)):
-            self.assertTrue((origin[i] - loaded_result[i]).abs().max() < 1e-10)
-            for k, v in origin_layer[i]._linear.weight.__dict__.items():
-                self.assertTrue(v == loaded_layer[i]._linear.weight.__dict__[k])
-
 
 if __name__ == '__main__':
     unittest.main()

python/paddle/framework/io.py

@@ -229,13 +229,9 @@ def _pickle_save(obj, f, protocol):
         raise ValueError("Expected 1<'protocol'<5, but received protocol={}".
                          format(protocol))
 
-    list_params = set()
-
     def reduce_varbase(self):
         data = self.numpy()
         name = self.name
-        if name in list_params:
-            return self.__reduce__()
 
         return (tuple, ((name, data), ))
 
@@ -245,19 +241,8 @@ def _pickle_save(obj, f, protocol):
         return (eval, ('data', {'data': data}))
 
     def reduce_Layer(self):
-        is_param_or_layer = lambda v: isinstance(v, ParamBase) or isinstance(v, core.Layer)
-
-        def collect_params(param_or_layer):
-            if isinstance(param_or_layer, ParamBase):
-                list_params.add(param_or_layer.name)
-            else:
-                # param_or_layer is layer
-                _parse_every_object(param_or_layer.__dict__, is_param_or_layer,
-                                    collect_params)
-            return param_or_layer
-
-        _parse_every_object(self.__dict__, is_param_or_layer, collect_params)
-        return self.__reduce_ex__(protocol)
+        raise ValueError(
+            "paddle do not support saving `paddle.nn.Layer` object.")
 
     dispatch_table_layer = dict()
 
@@ -567,7 +552,7 @@ def save(obj, path, protocol=4, **configs):
     Save an object to the specified path.
     
     .. note::
-        Now supports saving ``state_dict`` of Layer/Optimizer, Layer, Tensor and nested structure containing Tensor, Program.
+        Now supports saving ``state_dict`` of Layer/Optimizer, Tensor and nested structure containing Tensor, Program.
 
     .. note::
         Different from ``paddle.jit.save``, since the save result of ``paddle.save`` is a single file, 
@@ -783,7 +768,7 @@ def load(path, **configs):
     Load an object can be used in paddle from specified path.
 
     .. note::
-        Now supports loading ``state_dict`` of Layer/Optimizer, Layer, Tensor and nested structure containing Tensor, Program.
+        Now supports loading ``state_dict`` of Layer/Optimizer, Tensor and nested structure containing Tensor, Program.
 
     .. note::
         In order to use the model parameters saved by paddle more efficiently,