Hello,can someone please help me with this one,i had changed my code for some millions time,but still it says that i havent defined the function by_three.. maybe i dont see something.. my code for now looks like this

def cube(number):

number = number * number * number

return number

def by_three(number):

if number % 3 == 0:

return ('%s is divisible') % (cube(number))

elif number % 3 != 0:

return ('%s is not divisible') % (number)

else:

return ('by_three is False')