I am writing a program to compare two different files.

For each line in file1 i want to compare it to all the lines in file2, then go to the next line in file1.

the code i have below is not looping back to the next line in file1, can anyone give me any suggestions to help?
Code:
#! /usr/bin/env python

import sys
import fileinput

# Open the two files
f1 = open(sys.argv[1], "r")
...