add tensor.tolist() support (#32366)

python/paddle/__init__.py

@@ -150,6 +150,7 @@ from .tensor.manipulation import flip  #DEFINE_ALIAS
 from .tensor.manipulation import unbind  #DEFINE_ALIAS
 from .tensor.manipulation import roll  #DEFINE_ALIAS
 from .tensor.manipulation import chunk  #DEFINE_ALIAS
+from .tensor.manipulation import tolist  #DEFINE_ALIAS
 from .tensor.math import abs  #DEFINE_ALIAS
 from .tensor.math import acos  #DEFINE_ALIAS
 from .tensor.math import asin  #DEFINE_ALIAS

python/paddle/fluid/tests/unittests/test_tensor_to_list.py

+# Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import paddle.fluid as fluid
+import unittest
+import numpy as np
+import six
+import paddle
+
+
+class TensorToListTest(unittest.TestCase):
+    def setUp(self):
+        self.shape = [11, 25, 32, 43]
+
+    def test_tensor_tolist(self):
+        places = [fluid.CPUPlace()]
+        if fluid.core.is_compiled_with_cuda():
+            places.append(fluid.CUDAPlace(0))
+            places.append(fluid.CUDAPinnedPlace())
+
+        for p in places:
+            np_arr = np.reshape(
+                np.array(six.moves.range(np.prod(self.shape))), self.shape)
+            expectlist = np_arr.tolist()
+
+            t = paddle.to_tensor(np_arr, place=p)
+            tensorlist = t.tolist()
+
+            self.assertEqual(tensorlist, expectlist)
+
+
+if __name__ == '__main__':
+    unittest.main()

python/paddle/tensor/manipulation.py

@@ -16,7 +16,7 @@ from __future__ import print_function
 
 from ..fluid.layers import core
 from ..fluid.layer_helper import LayerHelper
-from ..fluid.framework import Variable, OpProtoHolder, in_dygraph_mode, convert_np_dtype_to_dtype_, device_guard
+from ..fluid.framework import Variable, OpProtoHolder, in_dygraph_mode, convert_np_dtype_to_dtype_, device_guard, dygraph_only
 from ..fluid.data_feeder import convert_dtype, check_variable_and_dtype, check_type, check_dtype
 from ..fluid.layers.tensor import fill_constant
 from ..fluid.layers import utils
@@ -76,6 +76,42 @@ def _print_warning_in_static_mode(api_name):
         format(api_name, api_name))
 
 
+@dygraph_only
+def tolist(x):
+    """
+    **Notes**:
+        **This API is ONLY available in Dygraph mode**
+
+    This function translate the paddle.Tensor to python list.
+
+    Args:
+        x(Tensor): ``x`` is the Tensor we want to translate to list
+
+    Returns:
+        list: A list that contain the same value of current Tensor.
+
+    Returns type:
+        list: dtype is same as current Tensor
+
+    Examples:
+        .. code-block:: python
+
+            import paddle
+
+            t = paddle.to_tensor([0,1,2,3,4])
+            expectlist = t.tolist()
+            print(expectlist)   #[0, 1, 2, 3, 4]
+
+            expectlist = paddle.tolist(t)
+            print(expectlist)   #[0, 1, 2, 3, 4]
+
+    """
+    return x.numpy().tolist()
+
+
+setattr(core.VarBase, 'tolist', tolist)
+
+
 def concat(x, axis=0, name=None):
     """