tee.py

#!/usr/bin/env python

import itertools

lines = ['one', 'two', 'three']

it, it_look_ahead = itertools.tee(lines)
next(it_look_ahead)

for line in it:
    print("this line: %s" % (line,))
    
    try:
        next_line = next(it_look_ahead)
    except StopIteration:
        pass
    else:
        print("next line: %s" % (next_line,))