fix(mge): fix scalar transpose

GitOrigin-RevId: c2b9e025c7

imperative/python/megengine/core/tensor/tensor_wrapper.py

@@ -392,6 +392,13 @@ class ArrayMethodMixin(abc.ABC):
         return _broadcast(self, _expand_args(args))
 
     def transpose(self, *args):
+        if self.ndim == 0:
+            assert (
+                len(args) == 0
+            ), "transpose for scalar does not accept additional args"
+            ret = self.to(self.device)
+            setscalar(ret)
+            return ret
         if not args:
             args = range(self.ndim)[::-1]
         return _transpose(self, _expand_args(args))

imperative/python/test/unit/test_zero_dim_tensor.py

@@ -50,3 +50,8 @@ def test_elemementwise():
 def test_astype():
     a = Tensor(1.0)
     assert a.astype("int32").ndim == 0
+
+
+def test_tranpose():
+    a = Tensor(1.0)
+    assert a.transpose().ndim == 0