fix eng doc for some api (#28477)

* fix eng doc, test=develop

* add import deprecated for layers, test=develop

* add block line for doc generate, test=develop

* remove todo for create_variable, test=develop

* add blank line for doc generate, test=develop

* add blank line for doc generate, test=develop

python/paddle/fluid/dygraph/layers.py

@@ -32,6 +32,7 @@ from ..param_attr import ParamAttr
 from paddle.fluid.executor import Executor, global_scope
 from paddle.fluid.framework import in_dygraph_mode
 from paddle.fluid.framework import _current_expected_place as _get_device
+import paddle.utils.deprecated as deprecated
 
 __all__ = ['Layer']
 
@@ -388,20 +389,74 @@ class Layer(core.Layer):
         return self._helper.create_parameter(temp_attr, shape, dtype, is_bias,
                                              default_initializer)
 
-    # TODO: Add more parameter list when we need them
+    @deprecated(
+        since="2.0.0",
+        update_to="paddle.nn.Layer.create_tensor",
+        reason="New api in create_tensor, easier to use.")
     def create_variable(self, name=None, persistable=None, dtype=None):
-        """Create Variable for this layer.
+        """
+
+        Create Tensor for this layer.
 
         Parameters:
-            name(str, optional): name of the variable. Please refer to :ref:`api_guide_Name` . Default: None
-            persistable(bool, optional): if set this variable persistable. Default: False
+            name(str, optional): name of the tensor. Please refer to :ref:`api_guide_Name` . Default: None
+
+            persistable(bool, optional): if set this tensor persistable. Default: False
+
+            dtype(str, optional): data type of this parameter. If set str, it can be "bool", "float16", "float32", "float64","int8", "int16", "int32", "int64", "uint8" or "uint16". If set None, it will be "float32". Default: None
+
+        Returns:
+            Tensor, created Tensor.
+
+        Examples:
+            .. code-block:: python
+
+                import paddle
+
+                class MyLinear(paddle.nn.Layer):
+                    def __init__(self,
+                                in_features,
+                                out_features):
+                        super(MyLinear, self).__init__()
+                        self.linear = paddle.nn.Linear( 10, 10)
+                            
+                        self.back_var = self.create_variable(name = "linear_tmp_0", dtype=self._dtype)
+                    
+                    def forward(self, input):
+                        out = self.linear(input)
+                        paddle.assign( out, self.back_var)
+                        
+                        return out
+
+        """
+        if name is not None:
+            var_name = ".".join([self._full_name, name])
+        else:
+            var_name = unique_name.generate(".".join(
+                [self._full_name, "_generated_var"]))
+
+        return self._helper.main_program.current_block().create_var(
+            name=var_name,
+            persistable=persistable,
+            dtype=dtype,
+            type=core.VarDesc.VarType.LOD_TENSOR)
+
+    # TODO: Add more parameter list when we need them
+    def create_tensor(self, name=None, persistable=None, dtype=None):
+        """
+
+        Create Tensor for this layer.
+
+        Parameters:
+            name(str, optional): name of the tensor. Please refer to :ref:`api_guide_Name` . Default: None
+            persistable(bool, optional): if set this tensor persistable. Default: False
             dtype(str, optional): data type of this parameter.
                 If set str, it can be "bool",  "float16", "float32", "float64",
                 "int8", "int16", "int32", "int64", "uint8" or "uint16".
                 If set None, it will be "float32". Default: None
 
         Returns:
-            Tensor, created Variable.
+            Tensor, created Tensor.
 
         Examples:
             .. code-block:: python
@@ -415,7 +470,7 @@ class Layer(core.Layer):
                         super(MyLinear, self).__init__()
                         self.linear = paddle.nn.Linear( 10, 10)
                             
-                        self.back_var = self.create_variable(name = "linear_tmp_0", dtype=self._dtype)
+                        self.back_var = self.create_tensor(name = "linear_tmp_0", dtype=self._dtype)
                     
                     def forward(self, input):
                         out = self.linear(input)
@@ -1053,7 +1108,7 @@ class Layer(core.Layer):
 
     def __dir__(self):
         """
-        Return a list. Get all parameters, buffers(non-parameter variables), sublayers, method and attr of Layer.
+        Return a list. Get all parameters, buffers(non-parameter tensors), sublayers, method and attr of Layer.
 
         Examples:
             .. code-block:: python

python/paddle/fluid/dygraph/nn.py

@@ -2387,21 +2387,21 @@ class BilinearTensorProduct(layers.Layer):
         **bias** (Parameter): the learnable bias of this layer.
 
     Returns:
-       Variable: A 2-D Tensor of shape [batch_size, size].
+       Tensor: A 2-D Tensor of shape [batch_size, size].
 
     Examples:
        .. code-block:: python
 
-         import paddle.fluid as fluid
+        import paddle
         import numpy
 
-         with fluid.dygraph.guard():
         layer1 = numpy.random.random((5, 5)).astype('float32')
         layer2 = numpy.random.random((5, 4)).astype('float32')
-             bilinearTensorProduct = fluid.dygraph.nn.BilinearTensorProduct(
+        bilinearTensorProduct = paddle.nn.BilinearTensorProduct(
             input1_dim=5, input2_dim=4, output_dim=1000)
-             ret = bilinearTensorProduct(fluid.dygraph.base.to_variable(layer1),
-                                fluid.dygraph.base.to_variable(layer2))
+        ret = bilinearTensorProduct(paddle.to_tensor(layer1),
+                                    paddle.to_tensor(layer2))
+
     """
 
     def __init__(self,

python/paddle/nn/functional/common.py

@@ -725,7 +725,6 @@ def bilinear(x1, x2, weight, bias=None, name=None):
         import numpy
         import paddle.nn.functional as F
 
-        paddle.disable_static()
         x1 = numpy.random.random((5, 5)).astype('float32')
         x2 = numpy.random.random((5, 4)).astype('float32')
         w = numpy.random.random((1000, 5, 4)).astype('float32')

python/paddle/nn/layer/common.py

@@ -425,7 +425,6 @@ class Bilinear(layers.Layer):
         import paddle
         import numpy
 
-        paddle.disable_static()
         layer1 = numpy.random.random((5, 5)).astype('float32')
         layer2 = numpy.random.random((5, 4)).astype('float32')
         bilinear = paddle.nn.Bilinear(