ValueError: max() arg is an empty sequence for pandas dataframe

Question

dff = pd.Series([ 0.001215,0.001571,0.002944, 0.005101, 0.007357, 0.009988, 0.013653, 0.017936, 0.021971, 0.025590 ])
dff = pd.DataFrame(dff, columns=[\'A\'])
window