code sample for pandas-dev#46306

Author: simonjayhawkins

bisect/46306.py

@@ -0,0 +1,13 @@
+# BUG: replace method with np.nan produces incorrect results #46306
+
+import numpy as np
+import pandas as pd
+
+print(pd.__version__)
+
+df = pd.DataFrame({"A": [0, 1, 2], "B": [1, 0, 2]})
+result = df.replace({0: 1, 1: np.nan})
+print(result)
+
+expected = pd.DataFrame({"A": [1.0, np.nan, 2.0], "B": [np.nan, 1.0, 2.0]})
+pd.testing.assert_frame_equal(result, expected)