l_words = []
with open('c:\\english.txt', 'r') as f_in:
    for line in f_in:
        line = line.strip().upper()
l_words.append(line)
return l_words
l_words = ReadWordList()
l_words = {key: None for key in l_words}
t1 = datetime.now()
for i in range(10000):
    w = bi_contains(l_words, 'ZEBRA')
t2 = datetime.now()
print('After: ' + str(t2 - t1))
Most efficient way for a lookup/search in a huge list (python)