string = 'my name is luka 90/91, I live on the second floor luka 12345'
keyword = 'luka'
i = 0
while True:
    i = string.find(keyword, i)
if i < 0:
    break
j = i + len(keyword) + 5 + 1
print(string[i:j])
i = j
print 5 characters that come after a key word