python入门递归之阶乘

def recurursion(n):
    if n == 1:
        return 1
    else:
        return n * recurursion(n-1)

number = int(input("请输入一个整数："))
b = recurursion(number)
print("%d的乘阶是：%d" % (number,b))

分析：
 return 5*recurursion(4)
    return 4*recurursion(3)
        return 3*recurursion(2)
           return 2*recurursion(1)
(n=1)               return 1