code sample for pandas-dev#46837

Author: simonjayhawkins

bisect/46837.py

@@ -0,0 +1,15 @@
+# BUG: Setting multiple values via .loc produces NaNs with MultiIndex #46837
+
+import pandas as pd
+
+print(pd.__version__)
+
+i = pd.MultiIndex.from_product([(0, 1), (2, 3)])
+s = pd.Series([True] * 4, index=i)
+
+expected = s.copy()
+
+s.loc[0, :] = s.loc[0, :]
+print(s)
+
+pd.testing.assert_series_equal(s, expected)