Any good engineer knows there is no "best" solution, only tradeoffs. Save space. def even_flip_flop(number): even = True for _ in range(number):

Any good engineer knows there is no "best" solution, only tradeoffs. Save space. def even_flip_flop(number): even = True for _ in range(number): even = not even return even Ditto. Sure, this overflows the stack, but you look cool doing it. def even_recursive(number): return True if number == 0 else not even_recursive(number - 1) Save time. Just buy more RAM. table = [True, False] * 1000 # adjust to your needs def even_lookup(number): return table[number]