# Filename: fibonaci.py
# author by: stephen

def fib(n):        #定義一個函數叫 fib()
    if n <= 1:     #定義數列的前兩個元素為1 1
        return n
    else:
        return(fib(n-1)+fib(n-2))    #根據斐波那契數列的特性第n個元素等於前兩個元素之和

nterms = int(input("which element do you want to calculate of fibonacci?"))

if nterms <= 0:    #判斷如果用戶輸入的是負數或零就不計算
    print("please input positive number!")
else:
    print("Fibonaci is : ")
    for i in range(nterms):
        print i, fib(i)
 

[Python學習] 斐波那契數列 Fibonacci Sequence