diff --git a/pandas/tests/test_multilevel.py b/pandas/tests/test_multilevel.py index 199307dd138ca..8c5f9a894f2f7 100644 --- a/pandas/tests/test_multilevel.py +++ b/pandas/tests/test_multilevel.py @@ -290,6 +290,30 @@ def test_datetime_object_multiindex(self): tm.assert_frame_equal(result, expected) + def test_multiindex_with_na(self): + df = DataFrame( + [ + ["A", np.nan, 1.23, 4.56], + ["A", "G", 1.23, 4.56], + ["A", "D", 9.87, 10.54], + ], + columns=["pivot_0", "pivot_1", "col_1", "col_2"], + ).set_index(["pivot_0", "pivot_1"]) + + df.at[("A", "F"), "col_2"] = 0.0 + + expected = DataFrame( + [ + ["A", np.nan, 1.23, 4.56], + ["A", "G", 1.23, 4.56], + ["A", "D", 9.87, 10.54], + ["A", "F", np.nan, 0.0], + ], + columns=["pivot_0", "pivot_1", "col_1", "col_2"], + ).set_index(["pivot_0", "pivot_1"]) + + tm.assert_frame_equal(df, expected) + class TestSorted: """everything you wanted to test about sorting"""