[RUNTIME][PYTHON] More compatibility in ndarray (#463)

python/tvm/_ffi/ndarray.py

@@ -165,6 +165,10 @@ class NDArrayBase(_NDArrayBase):
         arr : NDArray
             Reference to self.
         """
+        if isinstance(source_array, NDArrayBase):
+            source_array.copyto(self)
+            return self
+
         if not isinstance(source_array, np.ndarray):
             try:
                 source_array = np.array(source_array, dtype=self.dtype)
@@ -187,6 +191,14 @@ class NDArrayBase(_NDArrayBase):
         check_call(_LIB.TVMArrayCopyFromBytes(self.handle, data, nbytes))
         return self
 
+    def __repr__(self):
+        res = "<tvm.NDArray shape={0}, {1}>\n".format(self.shape, self.context)
+        res += self.asnumpy().__repr__()
+        return res
+
+    def __str__(self):
+        return str(self.asnumpy())
+
     def asnumpy(self):
         """Convert this array to numpy array
 

python/tvm/ndarray.py

@@ -140,7 +140,7 @@ def array(arr, ctx=cpu(0)):
     ret : NDArray
         The created array
     """
-    if not isinstance(arr, _np.ndarray):
+    if not isinstance(arr, (_np.ndarray, NDArray)):
         arr = _np.array(arr)
     return empty(arr.shape, arr.dtype, ctx).copyfrom(arr)