code sample for pandas-dev#47127

Author: simonjayhawkins

bisect/47127.py

@@ -0,0 +1,14 @@
+# BUG: concat column order behaviors changes after 1.4 #47127
+
+import pandas as pd
+
+print(pd.__version__)
+
+pdf = pd.DataFrame({"A": [0, 2, 4], "B": [1, 3, 5], "C": [6, 7, 8]})
+result = pd.concat(
+    [pdf, pdf["C"], pdf["A"]], ignore_index=True, join="outer", sort=True
+)
+print(result)
+
+expected = pd.Index([0, "A", "B", "C"], dtype="object")
+pd.testing.assert_index_equal(result.columns, expected)