for line in filename:
    if 'miles' in line: #checking for miles is straight forward
       #do whatever I have to do
    if 'Kilómetros' in line:#the problem is here
       #do whatever I have to do

text1 = 'abcabcabcabcabcabcabcabcabcabc'
for char in text1:
    if char not in ['a', 'b', 'c']:
       print('oops',text1)
text2 = 'abcabcabcabcaΞΞΞbcabcabcabcabcabc'
for char in text2:
    if char not in ['a', 'b', 'c']:
       print('oops',text2)