def fabs(n):

     a, b = 0, 1

     while b < n:

         print(b, end=' ')

         a, b = b, a+b

 fabs(1000)

 result = [0, 1]

 def fabs(n):

     while n-result[-1] > result[-2]:

         result.append(result[-2] + result[-1])

 fabs(100)

 print(result)

 class Fabs:

     def __init__(self, max):

         self.max = max

         self.a, self.b = 0, 1

     def __iter__(self):

         return self

     def next(self):

         if self.b<self.max:

             r = self.b

             self.a, self.b = self.b, self.a+self.b

             return r

 f1 = Fabs(1000)

 m = f1.next()

 while m:

     print(m, end=' ')

     m = f1.next()

 def fabs(n):

     a, b = 0, 1

     while b<n:

         yield b

         a, b = b, a+b

 if __name__ == '__main__':

     for i in fabs(1000):

         print(i, end=' ')