handle scalar and list

Author: guschmue

tf2onnx/onnx_opset/tensor.py

@@ -607,7 +607,9 @@ def version_7(cls, ctx, node, **kwargs):
         if dim_node.is_const():
             node.type = "Unsqueeze"
             dim = dim_node.get_tensor_value()
-            dim = dim[0]
+            # TODO: isn't this always a list ?
+            if isinstance(dim, list):
+                dim = dim[0]
             if dim < 0:
                 input_rank = len(ctx.get_shape(node.input[0]))
                 dim = dim + input_rank + 1