test=develop, fix space_to_depth_doc (#16293)

* test=develop, fix space_to_depth_doc

* test=develop, refine indent

* test=develop, refine code

* test=develop, add api spec

paddle/fluid/API.spec

@@ -211,7 +211,7 @@ paddle.fluid.layers.mean (ArgSpec(args=['x', 'name'], varargs=None, keywords=Non
 paddle.fluid.layers.mul (ArgSpec(args=['x', 'y', 'x_num_col_dims', 'y_num_col_dims', 'name'], varargs=None, keywords=None, defaults=(1, 1, None)), ('document', 'ccd37fa6b53f074adbfb732d738c4c2d'))
 paddle.fluid.layers.sigmoid_cross_entropy_with_logits (ArgSpec(args=['x', 'label', 'ignore_index', 'name', 'normalize'], varargs=None, keywords=None, defaults=(-100, None, False)), ('document', '180c284317ea45ef89a460d8d79c0b72'))
 paddle.fluid.layers.maxout (ArgSpec(args=['x', 'groups', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '891870d069a6aea746d34cc53b61690c'))
-paddle.fluid.layers.space_to_depth (ArgSpec(args=['x', 'blocksize', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '5f207ae10589ebe38a63575ef6ff8e1e'))
+paddle.fluid.layers.space_to_depth (ArgSpec(args=['x', 'blocksize', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', 'a9221eaef53884a00654e028551b78e2'))
 paddle.fluid.layers.affine_grid (ArgSpec(args=['theta', 'out_shape', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '51def402b8910e163cbace9d0c0526ed'))
 paddle.fluid.layers.sequence_reverse (ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '77a6d80aa5551ca70324fc975c44507f'))
 paddle.fluid.layers.affine_channel (ArgSpec(args=['x', 'scale', 'bias', 'data_layout', 'name', 'act'], varargs=None, keywords=None, defaults=(None, None, 'NCHW', None, None)), ('document', 'ab84fdc6dc60f3ad9aa397e6007e3bf9'))

python/paddle/fluid/layers/nn.py

@@ -9674,9 +9674,15 @@ def space_to_depth(x, blocksize, name=None):
         .. code-block:: python
 
             data = fluid.layers.data(
-                name='data', shape=[1, 4, 2, 2], dtype='float32')
+                name='data', shape=[1, 4, 2, 2], dtype='float32', append_batch_size=False)
             space_to_depthed = fluid.layers.space_to_depth(
                 x=data, blocksize=2)
+
+            exe = fluid.Executor(fluid.CUDAPlace(0))
+            data_np = np.arange(0,16).reshape((1,4,2,2)).astype('float32')
+            out_main = exe.run(fluid.default_main_program(),
+                          feed={'data': data_np},
+                          fetch_list=[space_to_depthed])
     """
 
     helper = LayerHelper("space_to_depth", **locals())