Python - pomoc

Se primer, ki, ne vem zakaj, ne deluje:

contactlist = open("document1","r")
contactfreq = open("document2","r")

limo = contactlist.readlines()
for line in contactfreq.readlines():
fils = line.split()
protein1 = fils[0]
protein2 = fils[1]
freq = fils[2]
list = (protein1+'\t'+protein2)
for lime in limo:
fiel = lime.split()
nup1 = fiel[0]
nup2 = fiel[1]
list1 = (nup1+'\t'+ nup2)
list2 = (nup2+'\t'+nup1)
if list == list1 or list == list2:
print protein1+'\t'+protein2+'\t'+freq+'\t'+'1';
break
if list != list1 and list != list2:
print protein1+'\t'+protein2+'\t'+freq+'\t'+'0';