How about simplifying the logic a bit:
def compare():
for i in range(len(list1)):
if list1[i] + list2[i] == 1:
return 0
return 1
--
David Eppstein UC Irvine Dept. of Information & Computer Science
eppstein at ics.uci.edu http://www.ics.uci.edu/~eppstein/