modify Sequential doc, test=develop

python/paddle/fluid/dygraph/container.py

@@ -34,26 +34,25 @@ class Sequential(Layer):
     Examples:
         .. code-block:: python
 
-            import paddle.fluid as fluid
+            import paddle
             import numpy as np
 
             data = np.random.uniform(-1, 1, [30, 10]).astype('float32')
-            with fluid.dygraph.guard():
-                data = fluid.dygraph.to_variable(data)
+            data = paddle.to_tensor(data)
             # create Sequential with iterable Layers
-                model1 = fluid.dygraph.Sequential(
-                    fluid.Linear(10, 1), fluid.Linear(1, 2)
+            model1 = paddle.nn.Sequential(
+                paddle.nn.Linear(10, 1), paddle.nn.Linear(1, 2)
             )
             model1[0]  # access the first layer
             res1 = model1(data)  # sequential execution
 
             # create Sequential with name Layer pairs
-                model2 = fluid.dygraph.Sequential(
-                    ('l1', fluid.Linear(10, 2)),
-                    ('l2', fluid.Linear(2, 3))
+            model2 = paddle.nn.Sequential(
+                ('l1', paddle.nn.Linear(10, 2)),
+                ('l2', paddle.nn.Linear(2, 3))
             )
             model2['l1']  # access l1 layer
-                model2.add_sublayer('l3', fluid.Linear(3, 3))  # add sublayer
+            model2.add_sublayer('l3', paddle.nn.Linear(3, 3))  # add sublayer
             res2 = model2(data)  # sequential execution
 
     """