修复 paddle.assign 等 API 的文档 (#42942)

* Update creation.py

* Update search.py

* Update search.py

* Update xavier.py

* Update xavier.py

* Update pooling.py

* Update pooling.py

* Update pooling.py

* Update search.py

python/paddle/nn/functional/pooling.py

@@ -1273,24 +1273,20 @@ def max_pool3d(x,
 
 def adaptive_avg_pool1d(x, output_size, name=None):
     """
-    This API implements adaptive average pooling 1d operation.
+    Adaptive average pooling 1d operation on :attr:`x` according to :attr:`output_size`. 
+    
+    Notes:
         See more details in :ref:`api_nn_pooling_AdaptiveAvgPool1d` .
 
     Args:
-        x (Tensor): The input tensor of pooling operator, which is a 3-D tensor
-                              with shape [N, C, L].  The format of input tensor is NCL,
-                              where N is batch size, C is the number of channels, L is the
-                              length of the feature. The data type is float32 or float64.
-        output_size (int): The target output size. It must be an integer.
-        name(str, optional): For detailed information, please refer
-                                 to :ref:`api_guide_Name`. Usually name is no need to set and
-                                 None by default.
+        x (Tensor): The input Tensor of pooling, which is a 3-D tensor with shape :math:`[N, C, L]`, where :math:`N` is batch size, :math:`C` is the number of channels and :math:`L` is the length of the feature. The data type is float32 or float64.
+        output_size (int): The target output size. Its data type must be int.
+        name (str, optional): For details, please refer to :ref:`api_guide_Name`. Generally, no setting is required. Default: None.
     Returns:
-            Tensor: The output tensor of adaptive average pooling result. The data type is same
-                      as input tensor.
+        Tensor: The result of 1D adaptive average pooling. Its data type is same as input.
     Examples:
         .. code-block:: python
-          :name: code-example1
+          :name: adaptive_avg_pool1d-example
 
               # average adaptive pool1d
               # suppose input data in shape of [N, C, L], `output_size` is m or [m],

python/paddle/nn/initializer/xavier.py

@@ -22,28 +22,26 @@ class XavierNormal(XavierInitializer):
     This class implements the Xavier weight initializer from the paper
     `Understanding the difficulty of training deep feedforward neural
     networks <http://proceedings.mlr.press/v9/glorot10a/glorot10a.pdf>`_
-    by Xavier Glorot and Yoshua Bengio, using a normal distribution.
-
-    The mean is 0 and the standard deviation is
+    by Xavier Glorot and Yoshua Bengio, using a normal distribution whose mean is :math:`0` and standard deviation is
 
     .. math::
 
-        \sqrt{\frac{2.0}{fan\_in + fan\_out}}
+        \sqrt{\frac{2.0}{fan\_in + fan\_out}}.
 
 
     Args:
-        fan_in (float, optional): fan_in for Xavier initialization, It is
-                inferred from the tensor. The default value is None.
-        fan_out (float, optional): fan_out for Xavier initialization, it is
-                 inferred from the tensor. The default value is None.
-        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`.
+        fan_in (float, optional): fan_in for Xavier initialization, which is
+                inferred from the Tensor. The default value is None.
+        fan_out (float, optional): fan_out for Xavier initialization, which is
+                 inferred from the Tensor. The default value is None.
+        name (str, optional): For details, please refer to :ref:`api_guide_Name`. Generally, no setting is required. Default: None.
 
     Returns:
         A parameter initialized by Xavier weight, using a normal distribution.
 
     Examples:
         .. code-block:: python
+            :name: initializer_XavierNormal-example
 
             import paddle
 
@@ -81,25 +79,25 @@ class XavierUniform(XavierInitializer):
 
     This initializer is designed to keep the scale of the gradients
     approximately same in all the layers. In case of Uniform distribution,
-    the range is [-x, x], where
+    the range is :math:`[-x,x]`, where
 
     .. math::
 
-        x = \sqrt{\frac{6.0}{fan\_in + fan\_out}}
+        x = \sqrt{\frac{6.0}{fan\_in + fan\_out}}.
 
     Args:
-        fan_in (float, optional): fan_in for Xavier initialization, it is
-                inferred from the tensor. The default value is None.
-        fan_out (float, optional): fan_out for Xavier initialization, it is
-                 inferred from the tensor. The default value is None.
-        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`.
+        fan_in (float, optional): fan_in for Xavier initialization, which is
+                inferred from the Tensor. The default value is None.
+        fan_out (float, optional): fan_out for Xavier initialization, which is
+                 inferred from the Tensor. The default value is None.
+        name (str, optional): For details, please refer to :ref:`api_guide_Name`. Generally, no setting is required. Default: None.
 
     Returns:
         A parameter initialized by Xavier weight, using a uniform distribution.
 
     Examples:
         .. code-block:: python
+            :name: initializer_XavierUniform-example
 
             import paddle
 

python/paddle/nn/layer/pooling.py

@@ -619,42 +619,32 @@ class MaxPool3D(Layer):
 class AdaptiveAvgPool1D(Layer):
     r"""
 
-    This operation applies a 1D adaptive average pooling over an input signal composed
-    of several input planes, based on the input, output_size, return_mask parameters.
-    Input(X) and output(Out) are in NCL format, where N is batch
-    size, C is the number of channels, L is the length of the feature.
-    The output tensor shape will be [N, C, output_size].
+    A 1D adaptive average pooling over an input signal composed
+    of several input planes, based on :attr:`output_size`.
+    Input and output are in NCL format, where N is batch
+    size, C is the number of channels and L is the length of the feature.
+    The shape of output will be :math:`[N, C, output\_size]`.
 
-    For average adaptive pool1d:
+    The formulation for average adaptive pool1d is
 
     ..  math::
 
-        lstart &= floor(i * L_{in} / L_{out})
+        lstart &= \lfloor i * L_{in} / L_{out}\rfloor,
 
-        lend &= ceil((i + 1) * L_{in} / L_{out})
+        lend &= \lceil(i + 1) * L_{in} / L_{out}\rceil,
 
-        Output(i) &= \frac{ \sum Input[lstart:lend]}{lend - lstart}
+        Output(i) &= \frac{\sum Input[lstart:lend]}{lend - lstart}.
 
     Parameters:
-        output_size(int): The target output size. It must be an integer.
-        name(str, optional): For detailed information, please refer to :ref:`api_guide_Name`.
-            Usually name is no need to set and None by default.
+        output_size(int): The target output size. Its data type must be int.
+        name (str, optional): For details, please refer to :ref:`api_guide_Name`. Generally, no setting is required. Default: None.
 
     Returns:
-        A callable object of AdaptiveAvgPool1D.
-
-    Raises:
-        ValueError: 'output_size' should be an integer.
-
-    Shape:
-        - x(Tensor): 3-D tensor. The input tensor of adaptive avg pool1d operator, which is a 3-D tensor.
-          The data type can be float32, float64.
-        - output(Tensor): 3-D tensor. The output tensor of adaptive avg pool1d operator, which is a 3-D tensor.
-          The data type is same as input x.
+        A callable object for computing 1D adaptive average pooling.
 
     Examples:
         .. code-block:: python
-
+            :name: AdaptiveAvgPool1D-example
             # average adaptive pool1d
             # suppose input data in shape of [N, C, L], `output_size` is m or [m],
             # output shape is [N, C, m], adaptive pool divide L dimension

python/paddle/tensor/creation.py

@@ -1479,21 +1479,20 @@ def empty_like(x, dtype=None, name=None):
 def assign(x, output=None):
     """
 
-    The OP copies the :attr:`x` to the :attr:`output`.
+    Copy value of the :attr:`x` to the :attr:`output`.
  
     Parameters:
-        x (Tensor|np.ndarray|list|tuple|scalar): A tensor, numpy ndarray, tuple/list of scalar,
-            or scalar. Its data type supports float16, float32, float64, int32, int64, and bool.
-            Note: the float64 data will be converted to float32 because of current platform protobuf
+        x (Tensor|np.ndarray|list|tuple|scalar): A Tensor, numpy ndarray, tuple/list of scalar,
+            or scalar. Its data type can be float16, float32, float64, int32, int64 or bool. Note: the float64 data will be converted to float32 because of current platform protobuf
             data limitation.
-        output (Tensor, optional): A tensor. If :attr:`output` is None, a new tensor will
-            be created as :attr:`output`. Default: None.
+        output (Tensor, optional): A Tensor. If :attr:`output` is None, a new Tensor will be created as :attr:`output`. Default: None.
  
     Returns:
-        Tensor: A tensor with the same shape, data type and value as :attr:`x`.
+        Tensor: A Tensor with the same shape, data type and value as :attr:`x`.
  
     Examples:
         .. code-block:: python
+          :name: assign-example
 
           import paddle
           import numpy as np

python/paddle/tensor/search.py

@@ -572,34 +572,31 @@ def mode(x, axis=-1, keepdim=False, name=None):
 
 def where(condition, x=None, y=None, name=None):
     r"""
-    Return a tensor of elements selected from either $x$ or $y$, depending on $condition$.
-
-    **Note**:
-        ``paddle.where(condition)`` is identical to ``paddle.nonzero(condition, as_tuple=True)``.
+    Return a Tensor of elements selected from either :attr:`x` or :attr:`y` according to corresponding elements of :attr:`condition`. Concretely,
 
     .. math::
 
         out_i =
         \begin{cases}
-      x_i, \quad  \text{if}  \ condition_i \  is \ True \\
-      y_i, \quad  \text{if}  \ condition_i \  is \ False \\
-      \end{cases}
+        x_i, & \text{if}  \ condition_i \  \text{is} \ True \\
+        y_i, & \text{if}  \ condition_i \  \text{is} \ False \\
+        \end{cases}.
 
+    Notes:
+        ``numpy.where(condition)`` is identical to ``paddle.nonzero(condition, as_tuple=True)``, please refer to :ref:`api_tensor_search_nonzero`.
 
     Args:
-        condition(Tensor): The condition to choose x or y. When True(nonzero), yield x, otherwise yield y.
-        x(Tensor or Scalar, optional): x is a Tensor or Scalar with data type float32, float64, int32, int64. Either both or neither of x and y should be given.
-        y(Tensor or Scalar, optional): y is a Tensor or Scalar with data type float32, float64, int32, int64. Either both or neither of x and y should be given.
-
-        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`.
+        condition (Tensor): The condition to choose x or y. When True (nonzero), yield x, otherwise yield y.
+        x (Tensor|scalar, optional): A Tensor or scalar to choose when the condition is True with data type of float32, float64, int32 or int64. Either both or neither of x and y should be given.
+        y (Tensor|scalar, optional): A Tensor or scalar to choose when the condition is False with data type of float32, float64, int32 or int64. Either both or neither of x and y should be given.
+        name (str, optional): For details, please refer to :ref:`api_guide_Name`. Generally, no setting is required. Default: None.
 
     Returns:
-        Tensor: A Tensor with the same data dype as x. 
+        Tensor: A Tensor with the same shape as :attr:`condition` and same data type as :attr:`x` and :attr:`y`.
 
     Examples:
         .. code-block:: python
+            :name:where-example
 
             import paddle