TST: paramterizes pos and neg tests

Author: deniederhut

pandas/tests/frame/test_operators.py

@@ -341,42 +341,48 @@ def test_logical_with_nas(self):
         expected = Series([True, True])
         assert_series_equal(result, expected)
 
-    def test_neg(self):
-        numeric = pd.DataFrame({
-            'a': [-1, 0, 1],
-            'b': [1, 0, 1],
-        })
-        boolean = pd.DataFrame({
-            'a': [True, False, True],
-            'b': [False, False, True]
-        })
-        timedelta = pd.Series(pd.to_timedelta([-1, 0, 10]))
-        not_numeric = pd.DataFrame({'string': ['a', 'b', 'c']})
-        assert_frame_equal(-numeric, -1 * numeric)
-        assert_frame_equal(-boolean, ~boolean)
-        assert_series_equal(-timedelta, pd.to_timedelta(-1 * timedelta))
+    @pytest.mark.parametrize('df,expected', [
+        (pd.DataFrame({'a': [-1, 1]}), pd.DataFrame({'a': [1, -1],})),
+        (pd.DataFrame({'a': [False, True]}), pd.DataFrame({'a': [True, False]})),
+        (pd.DataFrame({'a': pd.Series(pd.to_timedelta([-1, 1]))}),
+            pd.DataFrame({'a': pd.Series(pd.to_timedelta([1, -1]))}))
+        ])
+    def test_neg_numeric(self, df, expected):
+        assert_frame_equal(-df, expected)
+        assert_series_equal(-df['a'], expected['a'])
+
+    @pytest.mark.parametrize('df', [
+        pd.DataFrame({'a': ['a', 'b']}),
+        pd.DataFrame({'a': pd.to_datetime(['2017-01-22', '1970-01-01'])}),
+    ])
+    def test_neg_raises(self, df):
         with pytest.raises(TypeError):
-            (+ not_numeric)
+            (- df)
+        with pytest.raises(TypeError):
+            (- df['a'])
 
     def test_invert(self):
         assert_frame_equal(-(self.frame < 0), ~(self.frame < 0))
 
-    def test_pos(self):
-        numeric = pd.DataFrame({
-            'a': [-1, 0, 1],
-            'b': [1, 0, 1],
-        })
-        boolean = pd.DataFrame({
-            'a': [True, False, True],
-            'b': [False, False, True]
-        })
-        timedelta = pd.Series(pd.to_timedelta([-1, 0, 10]))
-        not_numeric = pd.DataFrame({'string': ['a', 'b', 'c']})
-        assert_frame_equal(+numeric, +1 * numeric)
-        assert_frame_equal(+boolean, (+1 * boolean).astype(bool))
-        assert_series_equal(+timedelta, pd.to_timedelta(+1 * timedelta))
+    @pytest.mark.parametrize('df', [
+        pd.DataFrame({'a': [-1, 1]}),
+        pd.DataFrame({'a': [False, True]}),
+        pd.DataFrame({'a': pd.Series(pd.to_timedelta([-1, 1]))}),
+    ])
+    def test_pos_numeric(self, df):
+        # GH 16073
+        assert_frame_equal(+df, df)
+        assert_series_equal(+df['a'], df['a'])
+
+    @pytest.mark.parametrize('df', [
+        pd.DataFrame({'a': ['a', 'b']}),
+        pd.DataFrame({'a': pd.to_datetime(['2017-01-22', '1970-01-01'])}),
+    ])
+    def test_pos_raises(self, df):
+        with pytest.raises(TypeError):
+            (+ df)
         with pytest.raises(TypeError):
-            (+ not_numeric)
+            (+ df['a'])
 
     def test_arith_flex_frame(self):
         ops = ['add', 'sub', 'mul', 'div', 'truediv', 'pow', 'floordiv', 'mod']