code sample for pandas-dev#38874

Author: simonjayhawkins

bisect/38874.py

@@ -0,0 +1,12 @@
+import pandas as pd
+
+print(pd.__version__)
+
+df = pd.DataFrame({"A": [1e-8, -1.1e-8, 1.2e-8, -1.1e-8] * 5})
+
+result = df["A"].rolling(10).std(ddof=0)
+print(result)
+
+expected = df["A"][-10:].std(ddof=0)
+
+assert result[19] == expected