Added pytest function

Same testing, but with pytest @parametrize

Author: jaehoonhwang

pandas/tests/tools/test_concat.py

@@ -1900,10 +1900,8 @@ def test_concat_multiindex_dfs_with_deepcopy(self):
         result_no_copy = pd.concat(example_dict, names=['testname'])
         tm.assert_frame_equal(result_no_copy, expected)
 
-
     def test_concat_no_unnecessary_upcats(self):
         # GH 13247
-
         for pdt in [pd.Series, pd.DataFrame, pd.Panel, pd.Panel4D]:
             dims = pdt().ndim
             for dt in np.sctypes['float']:
@@ -1913,9 +1911,9 @@ def test_concat_no_unnecessary_upcats(self):
                 x = pd.concat(dfs)
                 self.assertTrue(x.values.dtype == dt)
 
-            for dt in(np.sctypes['int'] + np.sctypes['uint']):
+            for dt in (np.sctypes['int'] + np.sctypes['uint']):
                 dfs = [pdt(np.array([1], dtype=dt, ndmin=dims)),
-                       pdt(np.array([5], dtype=dt ,ndmin=dims))]
+                       pdt(np.array([5], dtype=dt, ndmin=dims))]
                 x = pd.concat(dfs)
                 self.assertTrue(x.values.dtype == dt)
 
@@ -1934,3 +1932,31 @@ def test_concat_no_unnecessary_upcats(self):
             objs.append(pdt(np.array([1], dtype=np.int32, ndmin=dims)))
             objs.append(pdt(np.array([1], dtype=np.float16, ndmin=dims)))
             self.assertTrue(pd.concat(objs).values.dtype == np.float64)
+
+    @parametrize('dtype', np.sctypes('float'))
+    @parametrize('klass', [Series, DataFrame, Panel])
+    def test_concat_no_unnecessary_upcats_pytest(self, dtype, klass):
+        # GH 13247
+        for pdt in klass:
+            dims = pdt().ndim
+            for dt in dtype:
+                dfs = [pdt(np.array([1], dtype=dt, ndmin=dims)),
+                       pdt(np.array([np.nan], dtype=dt, ndmin=dims)),
+                       pdt(np.array([5], dtype=dt, ndmin=dims))]
+                x = pd.concat(dfs)
+                self.assertTrue(x.values.dtype == dt)
+
+            objs = []
+            objs.append(pdt(np.array([1], dtype=np.float32, ndmin=dims)))
+            objs.append(pdt(np.array([1], dtype=np.float16, ndmin=dims)))
+            self.assertTrue(pd.concat(objs).values.dtype == np.float32)
+
+            objs = []
+            objs.append(pdt(np.array([1], dtype=np.int32, ndmin=dims)))
+            objs.append(pdt(np.array([1], dtype=np.int64, ndmin=dims)))
+            self.assertTrue(pd.concat(objs).values.dtype == np.int64)
+
+            objs = []
+            objs.append(pdt(np.array([1], dtype=np.int32, ndmin=dims)))
+            objs.append(pdt(np.array([1], dtype=np.float16, ndmin=dims)))
+            self.assertTrue(pd.concat(objs).values.dtype == np.float64)