update whatsnew and tests

Author: reidy-p

doc/source/whatsnew/v0.22.0.txt

@@ -44,15 +44,14 @@ Other Enhancements
 - :class:`pandas.io.formats.style.Styler` now has method ``hide_columns()`` to determine whether columns will be hidden in output (:issue:`14194`)
 - Improved wording of ``ValueError`` raised in :func:`to_datetime` when ``unit=`` is passed with a non-convertible value (:issue:`14350`)
 - :func:`Series.fillna` now accepts a Series or a dict as a ``value`` for a categorical dtype (:issue:`17033`)
-- :func:`pandas.DataFrame.merge` no longer casts a ``float`` column to ``object`` when merging on ``int`` and ``float`` columns (:issue:`16572`)
 
 .. _whatsnew_0220.api_breaking:
 
 Backwards incompatible API changes
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 - :func:`Series.fillna` now raises a ``TypeError`` instead of a ``ValueError`` when passed a list, tuple or DataFrame as a ``value`` (:issue:`18293`)
--
+- :func:`pandas.DataFrame.merge` no longer casts a ``float`` column to ``object`` when merging on ``int`` and ``float`` columns (:issue:`16572`)
 -
 
 

pandas/tests/reshape/test_merge.py

@@ -1422,13 +1422,13 @@ def test_merge_on_ints_floats(self, int_vals, float_vals, exp_vals):
         # merging on float and int columns
         A = DataFrame({'X': int_vals})
         B = DataFrame({'Y': float_vals})
-        exp_res = DataFrame(exp_vals)
+        expected = DataFrame(exp_vals)
 
-        res = A.merge(B, left_on='X', right_on='Y')
-        assert_frame_equal(res, exp_res)
+        result = A.merge(B, left_on='X', right_on='Y')
+        assert_frame_equal(result, expected)
 
-        res = B.merge(A, left_on='Y', right_on='X')
-        assert_frame_equal(res, exp_res[['Y', 'X']])
+        result = B.merge(A, left_on='Y', right_on='X')
+        assert_frame_equal(result, expected[['Y', 'X']])
 
     def test_merge_on_ints_floats_warning(self):
         # GH 16572
@@ -1437,15 +1437,15 @@ def test_merge_on_ints_floats_warning(self):
         # equal to their int representation
         A = DataFrame({'X': [1, 2, 3]})
         B = DataFrame({'Y': [1.1, 2.5, 3.0]})
-        exp_res = DataFrame({'X': [3], 'Y': [3.0]})
+        expected = DataFrame({'X': [3], 'Y': [3.0]})
 
         with tm.assert_produces_warning(UserWarning):
-            res = A.merge(B, left_on='X', right_on='Y')
-            assert_frame_equal(res, exp_res)
+            result = A.merge(B, left_on='X', right_on='Y')
+            assert_frame_equal(result, expected)
 
         with tm.assert_produces_warning(UserWarning):
-            res = B.merge(A, left_on='Y', right_on='X')
-            assert_frame_equal(res, exp_res[['Y', 'X']])
+            result = B.merge(A, left_on='Y', right_on='X')
+            assert_frame_equal(result, expected[['Y', 'X']])
 
 
 @pytest.fixture