python 预设命令行变量代替raw_input 二次输入的方法

这个功能类似于shell命令行命令后面跟的参数，比如sh test.sh par1 par2 进行命令的执行，对于python有如下类似方法：

#!/usr/bin/env python
#-*- coding:utf-8 -*-
print '*' * 50

from sys import argv
script, first, second, third = argv

print "The script is called：", script
print "your first variable is:", first
print "a + b = ",int(second) + int(third)

root@loongson-desktop:/home/loongson/lijy-backup/lijy-test/test# python hardway_exe2.py 1st 50 300
**************************************************
The script is called： hardway_exe2.py
your first variable is: 1st
a + b =  350

这样就可以免去了后续用户的输入，直接一步到位。主要是对argv的调用，另外，参数是以字符串的形式进行读取的，所以用到数字时需要进行类型转换，否则按字符串处理，如下：

#!/usr/bin/env python
#-*- coding:utf-8 -*-
print '*' * 50

from sys import argv
script, first, second, third = argv

print "The script is called：", script
print "your first variable is:", first
print "a + b = ",second + third

输出如下，注意等号后的结果，只是把字符串连接起来了

root@loongson-desktop:/home/loongson/lijy-backup/lijy-test/test# python hardway_exe2.py 1st 50 300
**************************************************
The script is called： hardway_exe2.py
your first variable is: 1st
a + b =  50300

这样就避免了使用raw_input进行一个个参数的输入了，还是比较有用的。