初识 Python 4

Posted 2020-08-03

函数：判断是否是数字

法一：

vi 11.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()

保存并退出

[[email protected] day2]# python 11.py

please input something: 45

45 is a number

-----------------------------------------------

法二：

[[email protected] day2]# vi 12.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])

保存并退出

[[email protected] day2]# python 12.py 123

123 is a number

[[email protected] day2]# python 12.py 123kh

123kh is not a number

--------------------------------------

打印系统进程号

vi 13.py

#！/usr/bin/python

import sys

import os

def isNum(s):

    for i in s:

        if i not in ‘0123456789‘:

            return False

    return True

for i in os.listdir(‘/proc‘):

    if isNum(i):

        print i

保存并退出

[[email protected] day2]# python 13.py

1

2

3

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