import pandas as pd a = pd.read_csv('sales.csv',sep=',') R = pd.qcut(a['recency'],[0,0.25,0.5,0.75,1.0],['4','3','2','1']).astype('str') F = pd.qcut(a['frequency'],[0,0.25,0.5,0.75,1.0],['1','2','3','4']).astype('str') M = pd.qcut(a['monetary'],[0,0.25,0.5,0.75,1.0],['1','2','3','4']).astype('str') ...