Any particular reason you didn't go for the list comprehension? def pyChallenge(): print sum([el for el in range(1001) if not((el%5==0) or el%7==0))])

Any particular reason you didn't go for the list comprehension? def pyChallenge(): print sum([el for el in range(1001) if not((el%5==0) or el%7==0))]) # this call is needed to test your function pyChallenge()