1.多型別傳值和冗餘引數

多型別傳值：

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
 

冗餘引數：

>>> 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.函式的遞迴呼叫

遞迴的注意事項：

必須有最後的預設結果:

if n == 0

遞迴引數必須向預設結果收斂的：

factorial(n-1)

階乘指令碼：

#!/usr/bin/env python          

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

#  2018/11/28 11:57  

# 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)