Completed flex frame fill_value testcase

Author: eicchen

pandas/tests/frame/test_arithmetic.py

@@ -631,22 +631,36 @@ def test_arith_flex_frame_fill_value_corner(self, float_frame, axis):
         rng = np.random.default_rng(60)
         mask = rng.random(float_frame.shape) < 0.2
         left = float_frame.mask(mask)
-        right = left.iloc[0].value
+        right = left.iloc[0]
 
         result = left.add(right, axis=axis, fill_value=3)
 
         if axis == 0:  # axis = index, vertical
-            expected = result * np.nan
+            pad_num = abs(result.shape[0] - len(right))
+            mult_num = result.shape[1]
+            right_pad = np.pad(
+                right, (0, pad_num), mode="constant", constant_values=(np.nan)
+            )
+            right_df = DataFrame(
+                [right_pad] * mult_num, columns=result.index, index=result.columns
+            ).T
+
+            left = left.reindex_like(result)
 
         else:  # axis = columns, horizontal
-            right_df = DataFrame([right] * result.shape[0], index=result.index)
-            left_filled = left.fillna(3)
-            right_filled = right_df.fillna(3)
-            expected = right_filled + left_filled
-            expected = expected.mask(expected == 6, pd.NA)
-
-        print(result)
-        print(expected)
+            pad_num = abs(result.shape[1] - len(right))
+            mult_num = result.shape[0]
+            right_pad = np.pad(
+                right, (0, pad_num), mode="constant", constant_values=(np.nan)
+            )
+            right_df = DataFrame(
+                [right_pad] * mult_num, index=result.index, columns=result.columns
+            )
+
+        left_filled = left.fillna(3)
+        right_filled = right_df.fillna(3)
+        expected = right_filled + left_filled
+        expected = expected.mask(expected == 6, pd.NA)
 
         tm.assert_frame_equal(result, expected)