fix doc preblem (#32010)

python/paddle/distributed/collective.py

@@ -142,7 +142,7 @@ def get_group(id=0):
     Get group instance by group id.
 
     Args:
-        id (int): the group id
+        id (int): the group id. Default value is 0.
 
     Returns:
         Group: the group instance.
@@ -163,26 +163,24 @@ def get_group(id=0):
 def new_group(ranks=None, backend=None):
     """
 
-    Creates a new distributed comminication group.
+    Creates a new distributed communication group.
 
     Args:
-        ranks (list): The global ranks of group members, list as sorted.
+        ranks (list): The global ranks of group members.
         backend (str): The backend used to create group, only nccl is supported now.
 
     Returns:
-        Group: The group instance. Nerver return None.
+        Group: The group instance.
 
     Examples:
         .. code-block:: python
 
-            import numpy as np
             import paddle
 
             paddle.distributed.init_parallel_env()
-            tindata = np.random.random([10, 1000]).astype('float32')
-            tindata = paddle.to_tensor(tindata)
-            gid = paddle.distributed.new_group([2,4,6])
-            paddle.distributed.all_reduce(tindata, group=gid, use_calc_stream=False)
+            tindata = paddle.randn(shape=[2, 3])
+            gp = paddle.distributed.new_group([2,4,6])
+            paddle.distributed.all_reduce(tindata, group=gp, use_calc_stream=False)
 
     """
 
@@ -221,7 +219,7 @@ def new_group(ranks=None, backend=None):
         place = core.CUDAPlace(genv.device_id)
         core.NCCLParallelContext(strategy, place).init_with_ring_id(ring_id)
     else:
-        assert False
+        assert False, ("no cuda device found")
 
     return gp
 
@@ -234,8 +232,8 @@ def wait(tensor, group=None, use_calc_stream=True):
     Args:
         tensor (Tensor): The Tensor used before sync.
         group (Group): The Group instance to perform sync.
-        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False),
-            default to False.
+        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False).
+            Default to True.
 
     Returns:
         None.
@@ -243,13 +241,10 @@ def wait(tensor, group=None, use_calc_stream=True):
     Examples:
         .. code-block:: python
 
-
-            import numpy as np
             import paddle
 
             paddle.distributed.init_parallel_env()
-            tindata = np.random.random([10, 1000]).astype('float32')
-            tindata = paddle.to_tensor(tindata)
+            tindata = paddle.randn(shape=[2, 3])
             paddle.distributed.all_reduce(tindata, use_calc_stream=True)
             paddle.distributed.wait(tindata)
 
@@ -306,8 +301,8 @@ def broadcast(tensor, src, group=None, use_calc_stream=True):
             should be float16, float32, float64, int32 or int64.
         src (int): The source rank.
         group (Group): The group instance return by new_group or None for global default group.
-        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False),
-            default to True.
+        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False).
+            Default to True.
 
     Returns:
         None.
@@ -339,6 +334,7 @@ def broadcast(tensor, src, group=None, use_calc_stream=True):
 
     ring_id = 0 if group is None else group.id
     gsrc = src if group is None else group.get_group_rank(src)
+    assert gsrc >= 0, ("src rank out of group, need global rank")
 
     if in_dygraph_mode():
         return core.ops.c_broadcast(tensor, tensor, 'root', gsrc,
@@ -370,10 +366,10 @@ def all_reduce(tensor, op=ReduceOp.SUM, group=None, use_calc_stream=True):
     Args:
         tensor (Tensor): The input Tensor. It also works as the output Tensor. Its data type
             should be float16, float32, float64, int32 or int64.
-        op (ReduceOp.SUM|ReduceOp.MAX|ReduceOp.Min|ReduceOp.PROD): Optional. The operation used.
+        op (ReduceOp.SUM|ReduceOp.MAX|ReduceOp.Min|ReduceOp.PROD): Optional. The operation used. Default value is ReduceOp.SUM.
         group (Group): The group instance return by new_group or None for global default group.
-        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False),
-            default to True.
+        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False).
+            Default to True.
 
     Returns:
         None.
@@ -453,10 +449,10 @@ def reduce(tensor, dst, op=ReduceOp.SUM, group=None, use_calc_stream=True):
         tensor (Tensor): The output Tensor for the destination and the input Tensor otherwise. Its data type
             should be float16, float32, float64, int32 or int64.
         dst (int): The destination rank id.
-        op (ReduceOp.SUM|ReduceOp.MAX|ReduceOp.Min|ReduceOp.PROD): Optional. The operation used.
+        op (ReduceOp.SUM|ReduceOp.MAX|ReduceOp.Min|ReduceOp.PROD): Optional. The operation used. Default value is ReduceOp.SUM.
         group (Group): The group instance return by new_group or None for global default group.
-        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False),
-            default to True.
+        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False).
+            Default to True.
 
     Returns:
         None.
@@ -487,6 +483,7 @@ def reduce(tensor, dst, op=ReduceOp.SUM, group=None, use_calc_stream=True):
 
     ring_id = 0 if group is None else group.id
     gdst = dst if group is None else group.get_group_rank(dst)
+    assert gdst >= 0, ("dst rank out of group, need global rank")
 
     if in_dygraph_mode():
         if op == ReduceOp.SUM:
@@ -548,8 +545,8 @@ def all_gather(tensor_list, tensor, group=None, use_calc_stream=True):
         tensor (Tensor): The Tensor to send. Its data type
             should be float16, float32, float64, int32 or int64.
         group (Group): The group instance return by new_group or None for global default group.
-        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False),
-            default to True.
+        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False).
+            Default to True.
 
     Returns:
         None.
@@ -624,11 +621,11 @@ def scatter(tensor, tensor_list=None, src=0, group=None, use_calc_stream=True):
         tensor (Tensor): The output Tensor. Its data type
             should be float16, float32, float64, int32 or int64.
         tensor_list (list): A list of Tensors to scatter. Every element in the list must be a Tensor whose data type
-            should be float16, float32, float64, int32 or int64.
-        src (int): The source rank id.
+            should be float16, float32, float64, int32 or int64. Default value is None.
+        src (int): The source rank id. Default value is 0.
         group (Group): The group instance return by new_group or None for global default group.
-        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False),
-            default to True.
+        use_calc_stream (bool): Wether to use calculation stream (True) or communication stream (False).
+            Default to True.
 
     Returns:
         None.
@@ -664,6 +661,7 @@ def scatter(tensor, tensor_list=None, src=0, group=None, use_calc_stream=True):
 
     ring_id = 0 if group is None else group.id
     gsrc = src if group is None else group.get_group_rank(src)
+    assert gsrc >= 0, ("src rank out of group, need global rank")
     rank = _get_global_group().rank if group is None else group.rank
     nranks = _get_global_group().nranks if group is None else group.nranks