import difflib
import itertools
# min similarity ratio between strings
threshold_ratio = 0.75
for str_1, str_2 in itertools.combinations(str_list, 2):
ratio = difflib.SequenceMatcher(None, str_1, str_2).ratio()
if (ratio > threshold_ratio):
print '%ft%stt could be tt%s' % (ratio, str_1, str_2)