斐波那契数列

 1 ‘‘‘
 2 斐波那契数列
 3 1、输出第十个数字
 4     1,1,2,3,5,8....
 5 ‘‘‘
 6 def fei(n):
 7     a,b = [1,1]
 8     for i in range(n-1):
 9         a,b = b, a+b
10     return a
11 print(fei(10)) # 55
12 
13 # 递归
14 def fib(n):
15     if n ==1 or n ==2:
16         return 1
17     return fib(n-1) + fib(n-2)
18 print(fib(10))