modify compose en (#20217)

* modify compose en

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop,test=document_fix

* test=develop,test=document_fix

paddle/fluid/API.spec

@@ -96,7 +96,7 @@ paddle.fluid.io.DataLoader.from_generator (ArgSpec(args=['feed_list', 'capacity'
 paddle.fluid.io.cache (ArgSpec(args=['reader'], varargs=None, keywords=None, defaults=None), ('document', '1676886070eb607cb608f7ba47be0d3c'))
 paddle.fluid.io.map_readers (ArgSpec(args=['func'], varargs='readers', keywords=None, defaults=None), ('document', '2d0903e1d2f00b4f1d6618e6b5310121'))
 paddle.fluid.io.buffered (ArgSpec(args=['reader', 'size'], varargs=None, keywords=None, defaults=None), ('document', '0d6186f109feceb99f60ec50a0a624cb'))
-paddle.fluid.io.compose (ArgSpec(args=[], varargs='readers', keywords='kwargs', defaults=None), ('document', '884291104e1c3f37f33aae44b7deeb0d'))
+paddle.fluid.io.compose (ArgSpec(args=[], varargs='readers', keywords='kwargs', defaults=None), ('document', '81c933c8da58041d91f084dcf6322349'))
 paddle.fluid.io.chain (ArgSpec(args=[], varargs='readers', keywords=None, defaults=None), ('document', 'e0311508658a7e741fc39feea8be0ad2'))
 paddle.fluid.io.shuffle (ArgSpec(args=['reader', 'buf_size'], varargs=None, keywords=None, defaults=None), ('document', 'e42ea6fee23ce26b23cb142cd1d6522d'))
 paddle.fluid.io.firstn (ArgSpec(args=['reader', 'n'], varargs=None, keywords=None, defaults=None), ('document', 'c5bb8f7dd4f917f1569a368aab5b8aad'))

python/paddle/reader/decorator.py

@@ -207,16 +207,29 @@ def compose(*readers, **kwargs):
     The composed reader will output:
     (1, 2, 3, 4, 5)
 
-    :param readers: readers that will be composed together.
-    :param check_alignment: if True, will check if input readers are aligned
-        correctly. If False, will not check alignment and trailing outputs
-        will be discarded. Defaults to True.
-    :type check_alignment: bool
-
-    :return: the new data reader.
+    Args:
+        readers (Reader|list of Reader): readers that will be composed together. 
+        check_alignment(bool, optional): Indicates whether the input readers are checked for
+                              alignment. If True, whether input readers are aligned
+                              correctly will be checked, else alignment will not be checkout and trailing outputs
+                              will be discarded. Defaults to True.
+
+    Returns: 
+        the new data reader (Reader).
+
+    Raises:
+        ComposeNotAligned: outputs of readers are not aligned. This will not raise if check_alignment is set to False.
+  
+    Examples:
+        .. code-block:: python
 
-    :raises ComposeNotAligned: outputs of readers are not aligned.
-        Will not raise when check_alignment is set to False.
+          import paddle.fluid as fluid
+          def reader_creator_10(dur):
+              def reader():
+                 for i in range(10):
+                     yield i
+              return reader
+          reader = fluid.io.compose(reader_creator_10(0), reader_creator_10(0))
     """
     check_alignment = kwargs.pop('check_alignment', True)