If I have a dataframe like this:
DF = pd.DataFrame(data={\'A\':[-3,1,3,5,7,np.nan,2,4,6,-1], \'B\':[8,6,4,-2,-5,9,7,3,-3,3], \'C\':[-1,-4,4,2,6,-3,1,5,2,8], \
