[CodeStyle][py2] remove compat module (round)

python/paddle/compat.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 import six
-import math
 
 __all__ = []
 
@@ -197,30 +196,3 @@ def _to_bytes(obj, encoding):
         return obj
     else:
         return six.b(obj)
-
-
-# math related functions
-def round(x, d=0):
-    """
-    Compatible round which act the same behaviour in Python3.
-
-    Args:
-        x(float) : The number to round halfway.
-
-    Returns:
-        round result of x
-    """
-    if six.PY3:
-        # The official walkaround of round in Python3 is incorrect
-        # we implement according this answer: https://www.techforgeek.info/round_python.html
-        if x > 0.0:
-            p = 10**d
-            return float(math.floor((x * p) + math.copysign(0.5, x))) / p
-        elif x < 0.0:
-            p = 10**d
-            return float(math.ceil((x * p) + math.copysign(0.5, x))) / p
-        else:
-            return math.copysign(0.0, x)
-    else:
-        import __builtin__
-        return __builtin__.round(x, d)

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

@@ -236,18 +236,6 @@ def test_to_bytes(self):
         for i in l2:
             self.assertTrue(isinstance(i, bytes))
 
-    def test_round(self):
-        self.assertEqual(3.0, cpt.round(3.4))
-        self.assertEqual(4.0, cpt.round(3.5))
-        self.assertEqual(0.0, cpt.round(0.1))
-        self.assertEqual(0.0, cpt.round(0.0))
-        self.assertEqual(-0.0, cpt.round(-0.0))
-        self.assertEqual(-0.0, cpt.round(-0.1))
-        self.assertEqual(-3.0, cpt.round(-3.4))
-        self.assertEqual(-4.0, cpt.round(-3.5))
-        self.assertEqual(5.0, cpt.round(5))
-        self.assertRaises(TypeError, cpt.round, None)
-
 
 if __name__ == "__main__":
     unittest.main()

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

@@ -17,10 +17,20 @@
 import numpy as np
 import math
 import sys
-import paddle.compat as cpt
 from op_test import OpTest
 import paddle.fluid as fluid
 
+from decimal import Decimal, ROUND_HALF_UP
+
+
+def _round(x):
+    """In Python3 round function rounds to the nearest even number,
+    we use this function to make the result always round up when the
+    remainder is 0.5. See more at:
+    https://stackoverflow.com/questions/33019698/how-to-properly-round-up-half-float-numbers
+    """
+    return Decimal(x).to_integral_value(rounding=ROUND_HALF_UP)
+
 
 class TestROIPoolOp(OpTest):
 
@@ -67,10 +77,10 @@ def calc_roi_pool(self):
         for i in range(self.rois_num):
             roi = self.rois[i]
             roi_batch_id = int(roi[0])
-            roi_start_w = int(cpt.round(roi[1] * self.spatial_scale))
-            roi_start_h = int(cpt.round(roi[2] * self.spatial_scale))
-            roi_end_w = int(cpt.round(roi[3] * self.spatial_scale))
-            roi_end_h = int(cpt.round(roi[4] * self.spatial_scale))
+            roi_start_w = int(_round(roi[1] * self.spatial_scale))
+            roi_start_h = int(_round(roi[2] * self.spatial_scale))
+            roi_end_w = int(_round(roi[3] * self.spatial_scale))
+            roi_end_h = int(_round(roi[4] * self.spatial_scale))
 
             roi_height = int(max(roi_end_h - roi_start_h + 1, 1))
             roi_width = int(max(roi_end_w - roi_start_w + 1, 1))