[Tensor] remove useless import in tensor dir (#997)

colossalai/tensor/_ops/addmm.py

 import torch
 from typing import Union
 from colossalai.tensor.op_wrapper import colo_op_impl
-from colossalai.nn.layer.parallel_1d._utils import split_forward_gather_backward, reduce_input, reduce_grad
-from colossalai.nn.layer.utils import divide
-from colossalai.core import global_context as gpc
+from colossalai.nn.layer.parallel_1d._utils import reduce_input, reduce_grad
 from colossalai.tensor import ComputePattern, TensorSpec, ComputePattern, ParallelAction, ColoTensor
-from colossalai.tensor.graph import GraphOpNode, GraphGlobalEnv
 from colossalai.tensor import dist_spec
 
 

colossalai/tensor/_ops/embedding.py

 import torch
 from colossalai.tensor.op_wrapper import colo_op_impl
-from colossalai.context import ParallelMode
-from colossalai.nn.layer.parallel_1d._utils import split_forward_gather_backward, reduce_input, \
-    gather_forward_split_backward, reduce_grad
-from colossalai.nn.layer.utils import divide
+from colossalai.nn.layer.parallel_1d._utils import reduce_input
 from colossalai.core import global_context as gpc
-from packaging import version
 from colossalai.tensor import ComputePattern, TensorSpec, ComputePattern, ParallelAction, ColoTensor, dist_spec
 
 

colossalai/tensor/colo_tensor.py

@@ -3,10 +3,7 @@ from copy import copy
 import torch
 from typing import Tuple, Optional, Callable, Union
 from numpy import product
-from colossalai.core import global_context as gpc
-from colossalai.nn.layer.utils import divide
-from colossalai.tensor import TensorSpec, ComputePattern
-from colossalai.nn.layer.parallel_1d._utils import split_forward_gather_backward, gather_forward_split_backward
+from colossalai.tensor import TensorSpec
 from .const import TensorType
 from colossalai.tensor import dist_spec
 from colossalai.tensor.dist_spec_mgr import DistSpecManager

colossalai/tensor/dist_spec_mgr.py

-from math import dist
 from colossalai.tensor.dist_spec import _DistSpec
 from colossalai.nn.layer.utils import divide
 from numpy import prod