code sample for pandas-dev#39943

Author: simonjayhawkins

bisect/39943.py

@@ -0,0 +1,13 @@
+# BUG: unary operators on IntegerArray return shared mask creating inconsistencies when assigning null and non-null values #39943
+
+import pandas as pd
+import pandas.testing as tm
+
+print(pd.__version__)
+
+s = pd.Series([1, 2, 3], dtype="Int64")
+s2 = -s
+expected = s2.copy()
+s[0] = None
+print(s2)
+tm.assert_series_equal(s2, expected)