If you do not import the library “time“, can not add the “sleep“, and if not add the “sleep” of a second between on and off, It is quite possible that our eye will not perceive flicker.
Kama unaweza Usilete maktaba ya “wakati“, unaweza kuongeza na “usingizi“, na kama si kuongeza ya “usingizi” ya pili kati ya ndani na nje ya, Inawezekana kabisa kwamba macho yetu wala hamtatambua flicker.