[Eager] paddle.sort interface use final_state (#41934)

* [Eager] paddle.sort interface use final_state

* Add eager test case for paddle.sort()

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

@@ -21,6 +21,7 @@ import paddle.fluid.layers as layers
 import numpy as np
 import six
 import paddle.fluid.core as core
+from paddle.fluid.framework import _test_eager_guard
 
 
 class TestSortOnCPU(unittest.TestCase):
@@ -70,14 +71,19 @@ class TestSortDygraph(unittest.TestCase):
         else:
             self.place = core.CPUPlace()
 
-    def test_api_0(self):
+    def func_api_0(self):
         paddle.disable_static(self.place)
         var_x = paddle.to_tensor(self.input_data)
         out = paddle.sort(var_x)
         self.assertEqual((np.sort(self.input_data) == out.numpy()).all(), True)
         paddle.enable_static()
 
-    def test_api_1(self):
+    def test_api_0(self):
+        with _test_eager_guard():
+            self.func_api_0()
+        self.func_api_0()
+
+    def func_api_1(self):
         paddle.disable_static(self.place)
         var_x = paddle.to_tensor(self.input_data)
         out = paddle.sort(var_x, axis=-1)
@@ -85,3 +91,8 @@ class TestSortDygraph(unittest.TestCase):
             (np.sort(
                 self.input_data, axis=-1) == out.numpy()).all(), True)
         paddle.enable_static()
+
+    def test_api_1(self):
+        with _test_eager_guard():
+            self.func_api_1()
+        self.func_api_1()

python/paddle/tensor/search.py

@@ -92,7 +92,7 @@ def argsort(x, axis=-1, descending=False, name=None):
             #  [0 2 1 1]]]
     """
     if in_dygraph_mode():
-        _, ids, = _C_ops.final_state_argsort(x, axis, descending)
+        _, ids = _C_ops.final_state_argsort(x, axis, descending)
         return ids
 
     if _in_legacy_dygraph():
@@ -482,9 +482,13 @@ def sort(x, axis=-1, descending=False, name=None):
             #  [4. 7. 4. 6.]
             #  [5. 7. 7. 9.]]]
     """
-    if paddle.in_dynamic_mode():
-        out, _ = _C_ops.argsort(x, 'axis', axis, 'descending', descending)
-        return out
+    if in_dygraph_mode():
+        outs, _ = _C_ops.final_state_argsort(x, axis, descending)
+        return outs
+
+    if _in_legacy_dygraph():
+        outs, _ = _C_ops.argsort(x, 'axis', axis, 'descending', descending)
+        return outs
     helper = LayerHelper("sort", **locals())
     out = helper.create_variable_for_type_inference(
         dtype=x.dtype, stop_gradient=False)