add code sample for pandas-dev#36889

Author: simonjayhawkins

bisect/36889.py

@@ -0,0 +1,27 @@
+import numpy as np
+import pandas as pd
+
+pd.__version__
+
+
+result = (
+    pd.DataFrame({"foo": [2, 1], "bar": [2, 1]})
+    .groupby("foo", sort=False)
+    .rolling(1)
+    .min()
+)
+print(result)
+
+values = np.array([[2.0, 2.0], [1.0, 1.0]])
+
+columns = pd.Index(["foo", "bar"], dtype="object")
+
+index = pd.MultiIndex.from_tuples([(2, 0), (1, 1)], names=["foo", None])
+
+
+expected = pd.DataFrame(values, index=index, columns=columns)
+
+
+import pandas.testing as tm
+
+tm.assert_frame_equal(result, expected)