在Python函數中如何多類型傳值與遞歸調用

1.多類型傳值和冗余參數

多類型傳值：

def fun(x,y):

    return x +y

print fun(3,5)

8

print fun(*t)

3

def fun(x,y,z):

    return x + y + z

t1 = (1,2,3)

fun(*t1)

6

fun(*(2,4,5))

11

fun(1,*t)

4

print t

(1, 2)

fun(x=1,y=3,z=5)

9

>>> dic = {'x':1,'y':3,'z':6}

>>> fun(**dic)

10
冗余參數：

>>> def fun(x,*args,**kwargs):

...     print x

...     print args

...     print kwargs

...    

>>> fun(1)

1

()

{}

>>> fun(1,2)

1

(2,)

{}

>>> fun(1,2,3)

1

(2, 3)

{}

>>> t

(1, 2)

>>> fun(1,2,3,'a',[1,2],*t,a=3,**{'t':11,'p':22})

1

(2, 3, 'a', [1, 2], 1, 2)

{'a': 3, 'p': 22, 't': 11}

2.函數的遞歸調用

遞歸的注意事項：

必須有最后的默認結果:

if n == 0

遞歸參數必須向默認結果收斂的：

factorial(n-1)
階乘腳本：

#!/usr/bin/env python          

# -*- coding:utf-8 -*-

# Feng Xiaoqing      

# jiecheng.py        

# ======================

def factorial(n):

    sum = 0

    for i in range(1,n+1):

        sum += i

    return sum

print factorial(100)

另外一種方法：

def factorial(n):

    if n == 0:

        return 1

    else:

        return n * factorial(n-1)

print factorial(5)

求1-100相加的和：

def factorial(n):

    if n == 0:

        return 0

    else:

        return n + factorial(n-1)

print factorial(100)