test for loop in py3

output.txt

c
123
f
456
i
789

process.py

#!/usr/bin/env python3

f = open("./test1.txt")
content_f = f.read()
g = open("./test2.txt")
content_g = g.read()

lines_f = content_f.split(sep='\n')
lines_g = content_g.split(sep='\n')

for i in range(3):
    print(lines_f[i].split(sep=' ')[2])
    print( ''.join( str(j) for j in lines_g[i].split(sep=' ') ) )

test1.txt

a b c
d e f
g h i

test2.txt

1 2 3
4 5 6
7 8 9