l1 = l2 = l3 = l = [] with open('l1.csv', 'r') as f: for i in f: l1 = l1 + [i.replace('\n','')] with open('l2.csv', 'r') as f: for i in f: l2 = l2 + [i.replace('\n','')] with open('l3.csv', 'r') as f: for i in f: l3 = l3 + [i.replace('\n','')] for i in range(len(l1)): l = l1[i] + ',' + l2[i][l2[i].find(',')+1:] + ',' + l3[i][l3[i].find(',')+1:] print(l)