Initial test case

Author: eicchen

pandas/tests/frame/test_arithmetic.py

@@ -2199,3 +2199,19 @@ def test_mixed_col_index_dtype(using_infer_string):
             dtype = "string"
         expected.columns = expected.columns.astype(dtype)
     tm.assert_frame_equal(result, expected)
+
+
+def test_df_mul_series_fill_value():
+    # GH 61581
+    data = np.arange(50).reshape(10, 5)
+    columns = list("ABCDE")
+    df = DataFrame(data, columns=columns)
+    for i in range(5):
+        df.iat[i, i] = np.nan
+        df.iat[i + 1, i] = np.nan
+        df.iat[i + 4, i] = np.nan
+
+    df_result = df[["A", "B", "C", "D"]].mul(df["E"], axis=0, fill_value=5)
+    df_expected = df[["A", "B", "C", "D"]].mul(df["E"].fillna(5), axis=0)
+
+    tm.assert_frame_equal(df_result, df_expected)