fix undef var (#33825)

python/paddle/distributed/collective.py

@@ -19,6 +19,7 @@ from ..fluid.framework import Variable
 from ..fluid.framework import OpProtoHolder
 from ..fluid.framework import in_dygraph_mode
 from ..fluid.framework import convert_np_dtype_to_dtype_
+from ..fluid.framework import _varbase_creator
 from ..fluid.data_feeder import convert_dtype
 from ..fluid.data_feeder import check_variable_and_dtype
 from ..fluid.data_feeder import check_type
@@ -31,6 +32,7 @@ import paddle
 from .fleet import fleet
 import paddle.fluid as fluid
 import paddle.fluid.core as core
+import paddle.fluid.dygraph_utils as dygraph_utils
 
 __all__ = []
 
@@ -158,7 +160,7 @@ def get_group(id=0):
     """
 
     gm = _get_group_map()
-    return gm[group] if group in gm else None
+    return gm[id] if id in gm else None
 
 
 def barrier(group=None):
@@ -462,7 +464,6 @@ def all_reduce(tensor, op=ReduceOp.SUM, group=None, use_calc_stream=True):
                 tensor, 'use_calc_stream', use_calc_stream, 'ring_id', ring_id)
         else:
             raise ValueError("Unknown parameter: {}.".format(op))
-        return out
 
     check_variable_and_dtype(
         tensor, 'tensor', ['float16', 'float32', 'float64', 'int32', 'int64'],