[Python] Array gracefully fails on non-cpu device

python/pyarrow/array.pxi

@@ -956,6 +956,7 @@ cdef class Array(_PandasConvertible):
  +"two-and-a-half"
 
  """
+ self._assert_cpu()
  cdef c_string result
  with nogil:
  result = self.ap.Diff(deref(other.ap))
@@ -982,6 +983,7 @@ cdef class Array(_PandasConvertible):
  -------
  cast : Array
  """
+ self._assert_cpu()
  return _pc().cast(self, target_type, safe=safe,
  options=options, memory_pool=memory_pool)
 
@@ -1000,6 +1002,7 @@ cdef class Array(_PandasConvertible):
  -------
  view : Array
  """
+ self._assert_cpu()
  cdef DataType type = ensure_type(target_type)
  cdef shared_ptr[CArray] result
  with nogil:
@@ -1022,6 +1025,7 @@ cdef class Array(_PandasConvertible):
  sum : Scalar
  A scalar containing the sum value.
  """
+ self._assert_cpu()
  options = _pc().ScalarAggregateOptions(**kwargs)
  return _pc().call_function('sum', [self], options)
 
@@ -1034,6 +1038,7 @@ cdef class Array(_PandasConvertible):
  unique : Array
  An array of the same data type, with deduplicated elements.
  """
+ self._assert_cpu()
  return _pc().call_function('unique', [self])
 
  def dictionary_encode(self, null_encoding='mask'):
@@ -1052,6 +1057,7 @@ cdef class Array(_PandasConvertible):
  encoded : DictionaryArray
  A dictionary-encoded version of this array.
  """
+ self._assert_cpu()
  options = _pc().DictionaryEncodeOptions(null_encoding)
  return _pc().call_function('dictionary_encode', [self], options)
 
@@ -1064,6 +1070,7 @@ cdef class Array(_PandasConvertible):
  StructArray
  An array of <input type "Values", int64 "Counts"> structs
  """
+ self._assert_cpu()
  return _pc().call_function('value_counts', [self])
 
  @staticmethod
@@ -1101,10 +1108,12 @@ cdef class Array(_PandasConvertible):
  array : pyarrow.Array or pyarrow.ChunkedArray
  ChunkedArray is returned if object data overflows binary buffer.
  """
+ self._assert_cpu()
  return array(obj, mask=mask, type=type, safe=safe, from_pandas=True,
  memory_pool=memory_pool)
 
  def __reduce__(self):
+ self._assert_cpu()
  return _restore_array, \
  (_reduce_array_data(self.sp_array.get().data().get()),)
 
@@ -1172,6 +1181,7 @@ cdef class Array(_PandasConvertible):
 
  @property
  def null_count(self):
+ self._assert_cpu()
  return self.sp_array.get().null_count()
 
  @property
@@ -1191,9 +1201,8 @@ cdef class Array(_PandasConvertible):
  The dictionary of dictionary arrays will always be counted in their
  entirety even if the array only references a portion of the dictionary.
  """
- cdef:
- CResult[int64_t] c_size_res
-
+ self._assert_cpu()
+ cdef CResult[int64_t] c_size_res
  with nogil:
  c_size_res = ReferencedBufferSize(deref(self.ap))
  size = GetResultValue(c_size_res)
@@ -1210,20 +1219,22 @@ cdef class Array(_PandasConvertible):
  If a buffer is referenced multiple times then it will
  only be counted once.
  """
- cdef:
- int64_t total_buffer_size
-
+ self._assert_cpu()
+ cdef int64_t total_buffer_size
  total_buffer_size = TotalBufferSize(deref(self.ap))
  return total_buffer_size
 
  def __sizeof__(self):
+ self._assert_cpu()
  return super(Array, self).__sizeof__() + self.nbytes
 
  def __iter__(self):
+ self._assert_cpu()
  for i in range(len(self)):
  yield self.getitem(i)
 
  def __repr__(self):
+ self._assert_cpu()
  type_format = object.__repr__(self)
  return '{0}\n{1}'.format(type_format, str(self))
 
@@ -1252,6 +1263,8 @@ cdef class Array(_PandasConvertible):
  If the array should be rendered as a single line of text
  or if each element should be on its own line.
  """
+ self._assert_cpu()
+
  cdef:
  c_string result
  PrettyPrintOptions options
@@ -1287,6 +1300,7 @@ cdef class Array(_PandasConvertible):
  return self.to_string(**kwargs)
 
  def __str__(self):
+ self._assert_cpu()
  return self.to_string()
 
  def __eq__(self, other):
@@ -1307,6 +1321,8 @@ cdef class Array(_PandasConvertible):
  -------
  bool
  """
+ self._assert_cpu()
+ self.other._assert_cpu()
  return self.ap.Equals(deref(other.ap))
 
  def __len__(self):
@@ -1331,6 +1347,7 @@ cdef class Array(_PandasConvertible):
  -------
  array : boolean Array
  """
+ self._assert_cpu()
  options = _pc().NullOptions(nan_is_null=nan_is_null)
  return _pc().call_function('is_null', [self], options)
 
@@ -1342,12 +1359,14 @@ cdef class Array(_PandasConvertible):
  -------
  array : boolean Array
  """
+ self._assert_cpu()
  return _pc().call_function('is_nan', [self])
 
  def is_valid(self):
  """
  Return BooleanArray indicating the non-null values.
  """
+ self._assert_cpu()
  return _pc().is_valid(self)
 
  def fill_null(self, fill_value):
@@ -1364,6 +1383,7 @@ cdef class Array(_PandasConvertible):
  result : Array
  A new array with nulls replaced by the given value.
  """
+ self._assert_cpu()
  return _pc().fill_null(self, fill_value)
 
  def __getitem__(self, key):
@@ -1380,12 +1400,14 @@ cdef class Array(_PandasConvertible):
  -------
  value : Scalar (index) or Array (slice)
  """
+ self._assert_cpu()
  if isinstance(key, slice):
  return _normalize_slice(self, key)
 
  return self.getitem(_normalize_index(key, self.length()))
 
  cdef getitem(self, int64_t i):
+ self._assert_cpu()
  return Scalar.wrap(GetResultValue(self.ap.GetScalar(i)))
 
  def slice(self, offset=0, length=None):
@@ -1404,8 +1426,9 @@ cdef class Array(_PandasConvertible):
  -------
  sliced : RecordBatch
  """
- cdef:
- shared_ptr[CArray] result
+ self._assert_cpu()
+
+ cdef shared_ptr[CArray] result
 
  if offset < 0:
  raise IndexError('Offset must be non-negative')
@@ -1436,12 +1459,14 @@ cdef class Array(_PandasConvertible):
  taken : Array
  An array with the same datatype, containing the taken values.
  """
+ self._assert_cpu()
  return _pc().take(self, indices)
 
  def drop_null(self):
  """
  Remove missing values from an array.
  """
+ self._assert_cpu()
  return _pc().drop_null(self)
 
  def filter(self, object mask, *, null_selection_behavior='drop'):
@@ -1463,6 +1488,7 @@ cdef class Array(_PandasConvertible):
  An array of the same type, with only the elements selected by
  the boolean mask.
  """
+ self._assert_cpu()
  return _pc().filter(self, mask,
  null_selection_behavior=null_selection_behavior)
 
@@ -1488,6 +1514,7 @@ cdef class Array(_PandasConvertible):
  index : Int64Scalar
  The index of the value in the array (-1 if not found).
  """
+ self._assert_cpu()
  return _pc().index(self, value, start, end, memory_pool=memory_pool)
 
  def sort(self, order="ascending", **kwargs):
@@ -1507,16 +1534,20 @@ cdef class Array(_PandasConvertible):
  -------
  result : Array
  """
+ self._assert_cpu()
  indices = _pc().sort_indices(
  self,
  options=_pc().SortOptions(sort_keys=[("", order)], **kwargs)
  )
  return self.take(indices)
 
  def _to_pandas(self, options, types_mapper=None, **kwargs):
+ self._assert_cpu()
  return _array_like_to_pandas(self, options, types_mapper=types_mapper)
 
  def __array__(self, dtype=None, copy=None):
+ self._assert_cpu()
+
  if copy is False:
  try:
  values = self.to_numpy(zero_copy_only=True)
@@ -1566,6 +1597,8 @@ cdef class Array(_PandasConvertible):
  -------
  array : numpy.ndarray
  """
+ self._assert_cpu()
+
  cdef:
  PyObject* out
  PandasOptions c_options
@@ -1604,6 +1637,7 @@ cdef class Array(_PandasConvertible):
  -------
  lst : list
  """
+ self._assert_cpu()
  return [x.as_py() for x in self]
 
  def tolist(self):
@@ -1737,6 +1771,8 @@ cdef class Array(_PandasConvertible):
  A pair of PyCapsules containing a C ArrowSchema and ArrowArray,
  respectively.
  """
+ self._assert_cpu()
+
  cdef:
  ArrowArray* c_array
  ArrowSchema* c_schema
@@ -1883,6 +1919,28 @@ cdef class Array(_PandasConvertible):
  device = GetResultValue(ExportDevice(self.sp_array))
  return device.device_type, device.device_id
 
+ @property
+ def device_type(self):
+ """
+ The device type where the array resides.
+
+ Returns
+ -------
+ DeviceAllocationType
+ """
+ return _wrap_device_allocation_type(self.sp_array.get().device_type())
+
+ @property
+ def is_cpu(self):
+ """
+ Whether the array is CPU-accessible.
+ """
+ return self.device_type == DeviceAllocationType.CPU
+
+ def _assert_cpu(self):
+ if not self.is_cpu:
+ raise NotImplementedError("Implemented only for data on CPU device")
+
 
 cdef _array_like_to_pandas(obj, options, types_mapper):
  cdef:

python/pyarrow/includes/libarrow.pxd

@@ -234,6 +234,7 @@ cdef extern from "arrow/api.h" namespace "arrow" nogil:
  CStatus Validate() const
  CStatus ValidateFull() const
  CResult[shared_ptr[CArray]] View(const shared_ptr[CDataType]& type)
+ CDeviceAllocationType device_type()
 
  shared_ptr[CArray] MakeArray(const shared_ptr[CArrayData]& data)
  CResult[shared_ptr[CArray]] MakeArrayOfNull(