python学习笔记4—函数

函数定义：

def fun()

[[email protected] ~]# vim fun.py

#!/usr/bin/python

def fun():

sth = raw_input("Please input something")

try:

if type(int(sth))==type(1):

print "%s is a number" %sth

except ValueError:

print "%s is not number" %sth

fun()

[[email protected] ~]# python fun.py

Please input something34

34 is a number

[[email protected] ~]# python fun.py

Please input somethingdf

df is not number

python传递参数

[[email protected] ~]# vim isNum.py

#!/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])  #argv[1]指12或者abc，argv[0]指isNum.py

[[email protected] ~]# python isNum.py 12

12 is a number

[[email protected] ~]# python isNum.py abc

abc is not a number