diff --git a/pandas/tests/frame/methods/test_replace.py b/pandas/tests/frame/methods/test_replace.py index 444aa45155dbf..3bcc26e85e347 100644 --- a/pandas/tests/frame/methods/test_replace.py +++ b/pandas/tests/frame/methods/test_replace.py @@ -1388,3 +1388,18 @@ def test_replace_no_replacement_dtypes(self, dtype, value): df = pd.DataFrame(np.eye(2), dtype=dtype) result = df.replace(to_replace=[None, -np.inf, np.inf], value=value) tm.assert_frame_equal(result, df) + + @pytest.mark.parametrize("replacement", [np.nan, 5]) + def test_replace_with_duplicate_columns(self, replacement): + # GH 24798 + result = pd.DataFrame({"A": [1, 2, 3], "A1": [4, 5, 6], "B": [7, 8, 9]}) + result.columns = list("AAB") + + expected = pd.DataFrame( + {"A": [1, 2, 3], "A1": [4, 5, 6], "B": [replacement, 8, 9]} + ) + expected.columns = list("AAB") + + result["B"] = result["B"].replace(7, replacement) + + tm.assert_frame_equal(result, expected)