refine the index_select Op for API 2.0 test=develop (#25296)

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

@@ -83,7 +83,7 @@ class TestIndexSelectAPI(unittest.TestCase):
             x = fluid.layers.data(name='x', shape=[-1, 4])
             index = fluid.layers.data(
                 name='index', shape=[3], dtype='int32', append_batch_size=False)
-            z = paddle.index_select(x, index, dim=1)
+            z = paddle.index_select(x, index, axis=1)
             exe = fluid.Executor(fluid.CPUPlace())
             res, = exe.run(feed={'x': self.data_x,
                                  'index': self.data_index},
@@ -124,7 +124,7 @@ class TestIndexSelectAPI(unittest.TestCase):
         with fluid.dygraph.guard():
             x = fluid.dygraph.to_variable(self.data_x)
             index = fluid.dygraph.to_variable(self.data_index)
-            z = paddle.index_select(x, index, dim=1)
+            z = paddle.index_select(x, index, axis=1)
             np_z = z.numpy()
         expect_out = np.array([[1.0, 2.0, 2.0], [5.0, 6.0, 6.0],
                                [9.0, 10.0, 10.0]])

python/paddle/tensor/search.py

@@ -63,9 +63,9 @@ def argmax(input, axis=None, dtype=None, out=None, keepdims=False, name=None):
             Variable that meets the requirements to store the result of operation.
             if out is None, a new Varibale will be create to store the result. Defalut is None.
         keepdims(bool, optional): Keep the axis that do the select max.
-        name(str, optional): The name of output variable, normally there is no need for user to set this this property. 
-            Default value is None, the framework set the name of output variable.  
-
+        name(str, optional): The default value is None. Normally there is no
+            need for user to set this property. For more information, please
+            refer to :ref:`api_guide_Name`.
 
     Returns:
         Variable: A Tensor with data type int64.
@@ -135,7 +135,7 @@ def argmax(input, axis=None, dtype=None, out=None, keepdims=False, name=None):
     return out
 
 
-def index_select(input, index, dim=0):
+def index_select(x, index, axis=0, name=None):
     """
 	:alias_main: paddle.index_select
 	:alias: paddle.index_select,paddle.tensor.index_select,paddle.tensor.search.index_select
@@ -146,56 +146,60 @@ def index_select(input, index, dim=0):
     size as the length of `index`; other dimensions have the same size as in the `input` tensor. 
 
     Args:
-        input (Variable): The input tensor variable.
-        index (Variable): The 1-D tensor containing the indices to index.
-        dim (int): The dimension in which we index.
+        x (Variable): The input tensor variable.The dtype of x can be one of float32, float64, int32, int64.
+        index (Variable): The 1-D tensor containing the indices to index.the dtype of index can be int32 or int64.
+        axis (int, optional): The dimension in which we index. Default: if None, the axis is 0.
+        name(str, optional): The default value is None. Normally there is no
+            need for user to set this property. For more information, please
+            refer to :ref:`api_guide_Name`.
 
     Returns:
         Variable: A Tensor with same data type as `input`.
     
+    Raises:
+        TypeError: x must be a Variable and the dtype of x must be one of  float32, float64, int32 and int64.
+        TypeError: index must be a Variable adn the dtype of index must be int32 or int64.
+
     Examples:
         .. code-block:: python
             import paddle
-            import paddle.fluid as fluid
             import numpy as np
 
+            paddle.enable_imperative()  # Now we are in imperative mode
             data = np.array([[1.0, 2.0, 3.0, 4.0],
                              [5.0, 6.0, 7.0, 8.0],
                              [9.0, 10.0, 11.0, 12.0]])
             data_index = np.array([0, 1, 1]).astype('int32')
 
-            with fluid.dygraph.guard():
-                x = fluid.dygraph.to_variable(data)
-                index = fluid.dygraph.to_variable(data_index)
-                out_z1 = paddle.index_select(x, index)
-                print(out_z1.numpy())
+            x = paddle.imperative.to_variable(data)
+            index = paddle.imperative.to_variable(data_index)
+            out_z1 = paddle.index_select(x=x, index=index)
             #[[1. 2. 3. 4.]
             # [5. 6. 7. 8.]
             # [5. 6. 7. 8.]]
-                out_z2 = paddle.index_select(x, index, dim=1)
-                print(out_z2.numpy())
+            out_z2 = paddle.index_select(x=x, index=index, axis=1)
             #[[ 1.  2.  2.]
             # [ 5.  6.  6.]
             # [ 9. 10. 10.]]
     """
-    helper = LayerHelper("index_select", **locals())
+
     if in_dygraph_mode():
-        return core.ops.index_select(input, index, 'dim', dim)
+        return core.ops.index_select(x, index, 'dim', axis)
 
-    check_variable_and_dtype(input, 'x',
-                             ['float32', 'float64', 'int32', 'int64'],
-                             'paddle.tensor.search.index_sample')
+    helper = LayerHelper("index_select", **locals())
+    check_variable_and_dtype(x, 'x', ['float32', 'float64', 'int32', 'int64'],
+                             'paddle.tensor.search.index_select')
     check_variable_and_dtype(index, 'index', ['int32', 'int64'],
-                             'paddle.tensor.search.index_sample')
+                             'paddle.tensor.search.index_select')
 
-    out = helper.create_variable_for_type_inference(input.dtype)
+    out = helper.create_variable_for_type_inference(x.dtype)
 
     helper.append_op(
         type='index_select',
-        inputs={'X': input,
+        inputs={'X': x,
                 'Index': index},
         outputs={'Out': out},
-        attrs={'dim': dim})
+        attrs={'dim': axis})
     return out