python学习：函数传参数

#!/usr/bin/python

 

import sys

 

def isNum(s):

    for i in s:

        if i in '0123456789':

           pass

        else:

            print "%s is not a number" %s

            sys.exit()

    else:

        print "%s is a number" %s

 

isNum(sys.argv[1])

 

//函数判断是否为数字 

 

执行结果：

python 12.py aa

aa is not a number

[root@web10 day02]# python 12.py 123

123 is a number

[root@web10 day02]# python 12.py 123d

123d is not a number

 

#!/usr/bin/python

 

import sys

import os

 

def isNum(s):

    if s.isdigit():

       return True

    return False

 

for i in os.listdir('/proc'):

    if  isNum(i):

         print i

#同样的效果 更加的简洁