code sample for pandas-dev#38602

Author: simonjayhawkins

bisect/38602.py

@@ -0,0 +1,33 @@
+import sys
+
+import numpy as np
+
+import pandas as pd
+import pandas.testing as tm
+
+print(pd.__version__)
+
+data = np.broadcast_to(np.arange(2)[None, :], (3, 2))
+
+df_sorted = pd.DataFrame(
+    data, columns=pd.MultiIndex.from_product([["level_0"], ["a", "b"]]), dtype=int
+)
+
+df_unsorted = df_sorted.reindex(
+    pd.MultiIndex.from_product([["level_0"], ["b", "a"]]), axis=1
+)
+
+result = df_unsorted.loc[:, ("level_0", ["a", "b"])]
+print(result)
+
+expected = pd.DataFrame(
+    data, columns=pd.MultiIndex.from_product([["level_0"], ["a", "b"]])
+)
+
+
+try:
+    tm.assert_frame_equal(result, expected)
+except AssertionError:
+    pass
+else:
+    sys.exit(1)