diff --git a/python/paddle/compat.py b/python/paddle/compat.py
index c94132e43981f4f86fa0c084da38bbc19cfed8c2..c278041b4612626c1e9965b81a7f597e1f0c5a27 100644
--- a/python/paddle/compat.py
+++ b/python/paddle/compat.py
@@ -17,9 +17,6 @@ import math
 
 __all__ = []
 
-int_type = int
-long_type = int
-
 
 #  str and bytes related functions
 def to_text(obj, encoding='utf-8', inplace=False):
@@ -227,35 +224,3 @@ def round(x, d=0):
     else:
         import __builtin__
         return __builtin__.round(x, d)
-
-
-def floor_division(x, y):
-    """
-    Compatible division which act the same behaviour in Python3 and Python2,
-    whose result will be a int value of floor(x / y) in Python3 and value of
-    (x / y) in Python2.
-
-    Args:
-        x(int|float) : The number to divide.
-        y(int|float) : The number to be divided
-
-    Returns:
-        division result of x // y
-    """
-    return x // y
-
-
-# exception related functions
-def get_exception_message(exc):
-    """
-    Get the error message of a specific exception
-
-    Args:
-        exec(Exception) : The exception to get error message.
-
-    Returns:
-        the error message of exec
-    """
-    assert exc is not None
-
-    return str(exc)
diff --git a/python/paddle/fluid/core.py b/python/paddle/fluid/core.py
index 7c7fff32fb268cadd06449327d542d9435d2ede5..1654fd827e5ec76c87ec310a0da34db6a6d201ad 100644
--- a/python/paddle/fluid/core.py
+++ b/python/paddle/fluid/core.py
@@ -47,18 +47,17 @@ except ImportError as e:
     from .. import compat as cpt
     if os.name == 'nt':
         executable_path = os.path.abspath(os.path.dirname(sys.executable))
-        raise ImportError(
-            """NOTE: You may need to run \"set PATH=%s;%%PATH%%\"
+        raise ImportError("""NOTE: You may need to run \"set PATH=%s;%%PATH%%\"
         if you encounters \"DLL load failed\" errors. If you have python
         installed in other directory, replace \"%s\" with your own
         directory. The original error is: \n %s""" %
-            (executable_path, executable_path, cpt.get_exception_message(e)))
+                          (executable_path, executable_path, str(e)))
     else:
         raise ImportError(
             """NOTE: You may need to run \"export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH\"
         if you encounters \"libmkldnn.so not found\" errors. If you have python
         installed in other directory, replace \"/usr/local/lib\" with your own
-        directory. The original error is: \n""" + cpt.get_exception_message(e))
+        directory. The original error is: \n""" + str(e))
 except Exception as e:
     raise e
 
@@ -75,8 +74,7 @@ def avx_supported():
             has_avx = os.popen('cat /proc/cpuinfo | grep -i avx').read() != ''
         except Exception as e:
             sys.stderr.write('Can not get the AVX flag from /proc/cpuinfo.\n'
-                             'The original error is: %s\n' %
-                             cpt.get_exception_message(e))
+                             'The original error is: %s\n' % str(e))
         return has_avx
     elif sysstr == 'darwin':
         try:
@@ -85,7 +83,7 @@ def avx_supported():
         except Exception as e:
             sys.stderr.write(
                 'Can not get the AVX flag from machdep.cpu.features.\n'
-                'The original error is: %s\n' % cpt.get_exception_message(e))
+                'The original error is: %s\n' % str(e))
         if not has_avx:
             import subprocess
             pipe = subprocess.Popen(
@@ -155,8 +153,7 @@ def avx_supported():
                                                ctypes.c_size_t(0), ONE_PAGE)
         except Exception as e:
             sys.stderr.write('Failed getting the AVX flag on Windows.\n'
-                             'The original error is: %s\n' %
-                             cpt.get_exception_message(e))
+                             'The original error is: %s\n' % str(e))
         return (retval & (1 << avx_bit)) > 0
     else:
         sys.stderr.write('Do not get AVX flag on %s\n' % sysstr)
diff --git a/python/paddle/fluid/tests/unittests/dist_transformer.py b/python/paddle/fluid/tests/unittests/dist_transformer.py
index b37b70cfeed67fde49bb6f2bdcf28fce03f2030a..32478b8c5fada9bab5d87729327eb4172ad90b3a 100644
--- a/python/paddle/fluid/tests/unittests/dist_transformer.py
+++ b/python/paddle/fluid/tests/unittests/dist_transformer.py
@@ -27,7 +27,6 @@ import paddle.fluid as fluid
 import paddle.fluid.layers as layers
 from test_dist_base import TestDistRunnerBase, runtime_main, RUN_STEP
 import paddle.compat as cpt
-from paddle.compat import long_type
 
 const_para_attr = fluid.ParamAttr(initializer=fluid.initializer.Constant(0.001))
 const_bias_attr = const_para_attr
@@ -173,10 +172,10 @@ seq_len = ModelHyperParams.max_length
 input_descs = {
     # The actual data shape of src_word is:
     # [batch_size * max_src_len_in_batch, 1]
-    "src_word": [(batch_size, seq_len, long_type(1)), "int64", 2],
+    "src_word": [(batch_size, seq_len, 1), "int64", 2],
     # The actual data shape of src_pos is:
     # [batch_size * max_src_len_in_batch, 1]
-    "src_pos": [(batch_size, seq_len, long_type(1)), "int64"],
+    "src_pos": [(batch_size, seq_len, 1), "int64"],
     # This input is used to remove attention weights on paddings in the
     # encoder.
     # The actual data shape of src_slf_attn_bias is:
@@ -185,11 +184,11 @@ input_descs = {
     [(batch_size, ModelHyperParams.n_head, seq_len, seq_len), "float32"],
     # The actual data shape of trg_word is:
     # [batch_size * max_trg_len_in_batch, 1]
-    "trg_word": [(batch_size, seq_len, long_type(1)), "int64",
+    "trg_word": [(batch_size, seq_len, 1), "int64",
                  2],  # lod_level is only used in fast decoder.
     # The actual data shape of trg_pos is:
     # [batch_size * max_trg_len_in_batch, 1]
-    "trg_pos": [(batch_size, seq_len, long_type(1)), "int64"],
+    "trg_pos": [(batch_size, seq_len, 1), "int64"],
     # This input is used to remove attention weights on paddings and
     # subsequent words in the decoder.
     # The actual data shape of trg_slf_attn_bias is:
@@ -208,15 +207,15 @@ input_descs = {
     "enc_output": [(batch_size, seq_len, ModelHyperParams.d_model), "float32"],
     # The actual data shape of label_word is:
     # [batch_size * max_trg_len_in_batch, 1]
-    "lbl_word": [(batch_size * seq_len, long_type(1)), "int64"],
+    "lbl_word": [(batch_size * seq_len, 1), "int64"],
     # This input is used to mask out the loss of padding tokens.
     # The actual data shape of label_weight is:
     # [batch_size * max_trg_len_in_batch, 1]
-    "lbl_weight": [(batch_size * seq_len, long_type(1)), "float32"],
+    "lbl_weight": [(batch_size * seq_len, 1), "float32"],
     # These inputs are used to change the shape tensor in beam-search decoder.
-    "trg_slf_attn_pre_softmax_shape_delta": [(long_type(2), ), "int32"],
-    "trg_slf_attn_post_softmax_shape_delta": [(long_type(4), ), "int32"],
-    "init_score": [(batch_size, long_type(1)), "float32"],
+    "trg_slf_attn_pre_softmax_shape_delta": [(2, ), "int32"],
+    "trg_slf_attn_post_softmax_shape_delta": [(4, ), "int32"],
+    "init_score": [(batch_size, 1), "float32"],
 }
 
 # Names of word embedding table which might be reused for weight sharing.
diff --git a/python/paddle/fluid/tests/unittests/test_compat.py b/python/paddle/fluid/tests/unittests/test_compat.py
index 7ff25fcfddd38cd1e65c5086e4df52c512167b9b..e7ecdeda8b6c8d3ac83a95e825f4d22b658315ed 100644
--- a/python/paddle/fluid/tests/unittests/test_compat.py
+++ b/python/paddle/fluid/tests/unittests/test_compat.py
@@ -18,10 +18,6 @@ import paddle.compat as cpt
 
 class TestCompatible(unittest.TestCase):
 
-    def test_type(self):
-        self.assertEqual(cpt.int_type, int)
-        self.assertEqual(cpt.long_type, int)
-
     def test_to_text(self):
         self.assertIsNone(cpt.to_text(None))
 
@@ -252,30 +248,6 @@ class TestCompatible(unittest.TestCase):
         self.assertEqual(5.0, cpt.round(5))
         self.assertRaises(TypeError, cpt.round, None)
 
-    def test_floor_division(self):
-        self.assertEqual(0.0, cpt.floor_division(3, 4))
-        self.assertEqual(1.0, cpt.floor_division(4, 3))
-        self.assertEqual(2.0, cpt.floor_division(6, 3))
-        self.assertEqual(-2.0, cpt.floor_division(-4, 3))
-        self.assertEqual(-2.0, cpt.floor_division(-6, 3))
-        self.assertRaises(ZeroDivisionError, cpt.floor_division, 3, 0)
-        self.assertRaises(TypeError, cpt.floor_division, None, None)
-
-    def test_get_exception_message(self):
-        exception_message = "test_message"
-        self.assertRaises(AssertionError, cpt.get_exception_message, None)
-        try:
-            raise RuntimeError(exception_message)
-        except Exception as e:
-            self.assertEqual(exception_message, cpt.get_exception_message(e))
-            self.assertIsNotNone(e)
-
-        try:
-            raise Exception(exception_message)
-        except Exception as e:
-            self.assertEqual(exception_message, cpt.get_exception_message(e))
-            self.assertIsNotNone(e)
-
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/python/paddle/fluid/tests/unittests/test_dataset.py b/python/paddle/fluid/tests/unittests/test_dataset.py
index 83a16e43f391297126d6ace3b18e825c58e82d9d..13b6b9838ccdcbd83571fab1b71f819130a8194a 100644
--- a/python/paddle/fluid/tests/unittests/test_dataset.py
+++ b/python/paddle/fluid/tests/unittests/test_dataset.py
@@ -904,7 +904,7 @@ class TestDatasetWithFetchHandler(unittest.TestCase):
             print("warning: we skip trainer_desc_pb2 import problem in windows")
         except RuntimeError as e:
             error_msg = "dataset is need and should be initialized"
-            self.assertEqual(error_msg, cpt.get_exception_message(e))
+            self.assertEqual(error_msg, str(e))
         except Exception as e:
             self.assertTrue(False)
 
@@ -948,7 +948,7 @@ class TestDatasetWithFetchHandler(unittest.TestCase):
             print("warning: we skip trainer_desc_pb2 import problem in windows")
         except RuntimeError as e:
             error_msg = "dataset is need and should be initialized"
-            self.assertEqual(error_msg, cpt.get_exception_message(e))
+            self.assertEqual(error_msg, str(e))
         except Exception as e:
             self.assertTrue(False)
 
diff --git a/python/paddle/fluid/tests/unittests/test_exception.py b/python/paddle/fluid/tests/unittests/test_exception.py
index 266c83106f2eae05e30858505c246549a2153442..a3d9e744481b487d2f68625a074731b04b1fb908 100644
--- a/python/paddle/fluid/tests/unittests/test_exception.py
+++ b/python/paddle/fluid/tests/unittests/test_exception.py
@@ -28,8 +28,7 @@ class TestException(unittest.TestCase):
         try:
             core.__unittest_throw_exception__()
         except RuntimeError as ex:
-            self.assertIn("This is a test of exception",
-                          cpt.get_exception_message(ex))
+            self.assertIn("This is a test of exception", str(ex))
             exception = ex
 
         self.assertIsNotNone(exception)
diff --git a/python/paddle/fluid/tests/unittests/test_imperative_data_loader_exception.py b/python/paddle/fluid/tests/unittests/test_imperative_data_loader_exception.py
index 4cc6d813bf871ce18c8424d1635cba97f2cd5e99..a9fed3cae36c6dc3f9e04308158235878d8028f1 100644
--- a/python/paddle/fluid/tests/unittests/test_imperative_data_loader_exception.py
+++ b/python/paddle/fluid/tests/unittests/test_imperative_data_loader_exception.py
@@ -67,8 +67,7 @@ class TestDygraphDataLoaderWithException(unittest.TestCase):
                 for _ in loader():
                     print("test_single_process_with_thread_expection")
             except core.EnforceNotMet as ex:
-                self.assertIn("Blocking queue is killed",
-                              cpt.get_exception_message(ex))
+                self.assertIn("Blocking queue is killed", str(ex))
                 exception = ex
             self.assertIsNotNone(exception)
 
@@ -130,8 +129,7 @@ class TestDygraphDataLoaderWithException(unittest.TestCase):
                     for image, _ in loader():
                         fluid.layers.relu(image)
             except core.EnforceNotMet as ex:
-                self.assertIn("Blocking queue is killed",
-                              cpt.get_exception_message(ex))
+                self.assertIn("Blocking queue is killed", str(ex))
                 exception = ex
             self.assertIsNotNone(exception)
 
diff --git a/python/paddle/fluid/tests/unittests/test_imperative_data_loader_exit_func.py b/python/paddle/fluid/tests/unittests/test_imperative_data_loader_exit_func.py
index 8c201d85a9cdd82d63e6df021f24118ff0ce1bea..b1c2f7715b60bcbe3bc9724dc0de6b7f2456da1e 100644
--- a/python/paddle/fluid/tests/unittests/test_imperative_data_loader_exit_func.py
+++ b/python/paddle/fluid/tests/unittests/test_imperative_data_loader_exit_func.py
@@ -57,7 +57,7 @@ class TestRegisterExitFunc(unittest.TestCase):
         try:
             CleanupFuncRegistrar.register(5)
         except TypeError as ex:
-            self.assertIn("is not callable", cpt.get_exception_message(ex))
+            self.assertIn("is not callable", str(ex))
             exception = ex
         self.assertIsNotNone(exception)
 
diff --git a/python/paddle/fluid/tests/unittests/test_imperative_double_grad.py b/python/paddle/fluid/tests/unittests/test_imperative_double_grad.py
index ae1fe6d3706663cdaa9912c3a91a37ee738b6992..5fb80c80d9d12eb2ac671aea65b50f27af715ca3 100644
--- a/python/paddle/fluid/tests/unittests/test_imperative_double_grad.py
+++ b/python/paddle/fluid/tests/unittests/test_imperative_double_grad.py
@@ -109,7 +109,7 @@ class TestEagerGrad(TestCase):
             # allow_unused is false in default
             dx = fluid.dygraph.grad(out, [x, z])
         except ValueError as e:
-            error_msg = cpt.get_exception_message(e)
+            error_msg = str(e)
             assert error_msg.find("allow_unused") > 0
 
     def test_simple_example_eager_grad_not_allow_unused(self):
@@ -133,7 +133,7 @@ class TestEagerGrad(TestCase):
             # duplicate input will arise RuntimeError errors
             dx = fluid.dygraph.grad(out, [x, x])
         except RuntimeError as e:
-            error_msg = cpt.get_exception_message(e)
+            error_msg = str(e)
             assert error_msg.find("duplicate") > 0
 
     def test_simple_example_eager_grad_duplicate_input(self):
@@ -157,7 +157,7 @@ class TestEagerGrad(TestCase):
             # duplicate output will arise RuntimeError errors
             dx = fluid.dygraph.grad([out, out], [x])
         except RuntimeError as e:
-            error_msg = cpt.get_exception_message(e)
+            error_msg = str(e)
             assert error_msg.find("duplicate") > 0
 
     def test_simple_example_eager_grad_duplicate_output(self):
diff --git a/python/paddle/fluid/tests/unittests/test_imperative_signal_handler.py b/python/paddle/fluid/tests/unittests/test_imperative_signal_handler.py
index 3f2a897b6b3e03fa6c7fe8e3f49b4623bb546467..72be7aafaf0d3229a2f21e5f5df2a9da8b4c6bc9 100644
--- a/python/paddle/fluid/tests/unittests/test_imperative_signal_handler.py
+++ b/python/paddle/fluid/tests/unittests/test_imperative_signal_handler.py
@@ -55,7 +55,7 @@ class DygraphDataLoaderSingalHandler(unittest.TestCase):
                 set_child_signal_handler(id(self), test_process.pid)
                 time.sleep(5)
             except SystemError as ex:
-                self.assertIn("Fatal", cpt.get_exception_message(ex))
+                self.assertIn("Fatal", str(ex))
                 exception = ex
             return exception
 
@@ -88,8 +88,7 @@ class DygraphDataLoaderSingalHandler(unittest.TestCase):
                 set_child_signal_handler(id(self), test_process.pid)
                 time.sleep(5)
             except SystemError as ex:
-                self.assertIn("Segmentation fault",
-                              cpt.get_exception_message(ex))
+                self.assertIn("Segmentation fault", str(ex))
                 exception = ex
             return exception
 
@@ -122,7 +121,7 @@ class DygraphDataLoaderSingalHandler(unittest.TestCase):
                 set_child_signal_handler(id(self), test_process.pid)
                 time.sleep(5)
             except SystemError as ex:
-                self.assertIn("Bus error", cpt.get_exception_message(ex))
+                self.assertIn("Bus error", str(ex))
                 exception = ex
             return exception
 
diff --git a/python/paddle/fluid/tests/unittests/test_lookup_table_op.py b/python/paddle/fluid/tests/unittests/test_lookup_table_op.py
index 1470ae4df56c1399ea180436a69e4d9c06731742..ce79317866bc8d052d5bbfde98cbf5f2757b6c7c 100644
--- a/python/paddle/fluid/tests/unittests/test_lookup_table_op.py
+++ b/python/paddle/fluid/tests/unittests/test_lookup_table_op.py
@@ -82,7 +82,7 @@ class TestLookupTableOpWithTensorIdsAndPadding(TestLookupTableOpWithTensorIds):
         flatten_idx = ids.flatten()
         padding_idx = np.random.choice(flatten_idx, 1)[0]
         self.outputs['Out'][np.squeeze(ids == padding_idx)] = np.zeros(31)
-        self.attrs = {'padding_idx': cpt.long_type(padding_idx)}
+        self.attrs = {'padding_idx': padding_idx}
         self.check_output()
 
 
@@ -250,7 +250,7 @@ class TestLookupTableOpWithTensorIdsAndPaddingInt8(
         flatten_idx = ids.flatten()
         padding_idx = np.random.choice(flatten_idx, 1)[0]
         self.outputs['Out'][np.squeeze(ids == padding_idx)] = np.zeros(31)
-        self.attrs = {'padding_idx': cpt.long_type(padding_idx)}
+        self.attrs = {'padding_idx': padding_idx}
         self.check_output()
 
     def test_check_grad(self):
@@ -380,7 +380,7 @@ class TestLookupTableOpWithTensorIdsAndPaddingInt16(
         flatten_idx = ids.flatten()
         padding_idx = np.random.choice(flatten_idx, 1)[0]
         self.outputs['Out'][np.squeeze(ids == padding_idx)] = np.zeros(31)
-        self.attrs = {'padding_idx': cpt.long_type(padding_idx)}
+        self.attrs = {'padding_idx': padding_idx}
         self.check_output()
 
 
diff --git a/python/paddle/fluid/tests/unittests/test_lookup_table_v2_op.py b/python/paddle/fluid/tests/unittests/test_lookup_table_v2_op.py
index 5552d2cd68f5d95bffebe5022bc9dad2d7439176..3b0a093426053165b1be4cdb5402e78637767161 100644
--- a/python/paddle/fluid/tests/unittests/test_lookup_table_v2_op.py
+++ b/python/paddle/fluid/tests/unittests/test_lookup_table_v2_op.py
@@ -123,7 +123,7 @@ class TestLookupTableOpWithTensorIdsAndPadding(TestLookupTableOpWithTensorIds):
         flatten_idx = ids.flatten()
         padding_idx = np.random.choice(flatten_idx, 1)[0]
         self.outputs['Out'][np.squeeze(ids == padding_idx)] = np.zeros(31)
-        self.attrs = {'padding_idx': cpt.long_type(padding_idx)}
+        self.attrs = {'padding_idx': padding_idx}
         self.check_output()
 
 
diff --git a/python/paddle/fluid/tests/unittests/test_operator_desc.py b/python/paddle/fluid/tests/unittests/test_operator_desc.py
index 7cf5b36f764c021fb6904da6bc118d0edb8c5d37..2b2c7287014a90e3507bfbd2f151eb323a6ab2d6 100644
--- a/python/paddle/fluid/tests/unittests/test_operator_desc.py
+++ b/python/paddle/fluid/tests/unittests/test_operator_desc.py
@@ -31,15 +31,14 @@ class TestOperator(unittest.TestCase):
             self.assertFail()
         except ValueError as v_err:
             self.assertEqual(
-                cpt.get_exception_message(v_err),
+                str(v_err),
                 "`type` to initialized an Operator can not be None.")
         try:
             block.append_op(type="no_such_op")
             self.assertFail()
         except ValueError as a_err:
             self.assertEqual(
-                cpt.get_exception_message(a_err),
-                "Operator \"no_such_op\" has not been registered.")
+                str(a_err), "Operator \"no_such_op\" has not been registered.")
 
     def test_op_desc_creation(self):
         program = Program()
diff --git a/python/paddle/fluid/tests/unittests/test_optimizer.py b/python/paddle/fluid/tests/unittests/test_optimizer.py
index 8e127f3c60c0a4278edb43230f62554d3bb2b285..52ce642c0e7de3f8b5f0a1101f44ea0d0b16a5fd 100644
--- a/python/paddle/fluid/tests/unittests/test_optimizer.py
+++ b/python/paddle/fluid/tests/unittests/test_optimizer.py
@@ -990,7 +990,7 @@ class TestRecomputeOptimizer(unittest.TestCase):
         except NotImplementedError as e:
             self.assertEqual(
                 "load function is not supported by Recompute Optimizer for now",
-                cpt.get_exception_message(e))
+                str(e))
 
     def test_dropout(self):
         """
diff --git a/python/paddle/fluid/tests/unittests/test_prune.py b/python/paddle/fluid/tests/unittests/test_prune.py
index 4899d5c4d48839bfabef0c1cb2190eaa9a212b84..dc44f99d670b6f0c8ecd0cc0b277018bc936ca99 100644
--- a/python/paddle/fluid/tests/unittests/test_prune.py
+++ b/python/paddle/fluid/tests/unittests/test_prune.py
@@ -100,7 +100,7 @@ class TestPrune(unittest.TestCase):
         except ValueError as e:
             self.assertIn(
                 "All targets of Program._prune_with_input() can only be Variable or Operator",
-                cpt.get_exception_message(e))
+                str(e))
 
 
 def mock(self, program, feed, fetch, optimize_ops):
diff --git a/python/paddle/fluid/tests/unittests/test_zeros_op.py b/python/paddle/fluid/tests/unittests/test_zeros_op.py
index 84d83d6a7b560b6ecca9ca299227607eb322f789..3072a04f257d4b34726c8bf6f7ff6236a05e7fa0 100644
--- a/python/paddle/fluid/tests/unittests/test_zeros_op.py
+++ b/python/paddle/fluid/tests/unittests/test_zeros_op.py
@@ -103,7 +103,7 @@ class ApiZerosError(unittest.TestCase):
                 shape = [-1, 5]
                 out = paddle.zeros(shape)
             except Exception as e:
-                error_msg = cpt.get_exception_message(e)
+                error_msg = str(e)
                 assert error_msg.find("expected to be no less than 0") > 0
 
     def test_eager(self):
diff --git a/python/paddle/fluid/tests/unittests/xpu/test_lookup_table_v2_op_xpu.py b/python/paddle/fluid/tests/unittests/xpu/test_lookup_table_v2_op_xpu.py
index 77f09fc9864a6262aa355418a858d48cc43466db..6bb54c8f74edf63401abb236856e9a5f43783e53 100644
--- a/python/paddle/fluid/tests/unittests/xpu/test_lookup_table_v2_op_xpu.py
+++ b/python/paddle/fluid/tests/unittests/xpu/test_lookup_table_v2_op_xpu.py
@@ -95,7 +95,7 @@ class TestLookupTableOpWithTensorIdsAndPadding(TestLookupTableOpWithTensorIds):
         flatten_idx = ids.flatten()
         padding_idx = np.random.choice(flatten_idx, 1)[0]
         self.outputs['Out'][np.squeeze(ids == padding_idx)] = np.zeros(31)
-        self.attrs = {'padding_idx': cpt.long_type(padding_idx)}
+        self.attrs = {'padding_idx': padding_idx}
         self.check_output_with_place(place=paddle.XPUPlace(0))