应该是第多次学习python了，都是学习到一半，就停止了，这次要坚持下去，fighting！！！
函数学习：
raw_input() 从标准输入读取一个字符串并自动删除尾的换行符，并将读取到的数据赋值给指定变量
例子：
>>> num = raw_input('Enter login name')
Enter login name
>>> num = raw_input('Now enter a number:')
Now enter a number:1024
>>> print 'Doubling your number:%d' % (int(num) *2)
Doubling your number:2048
help() 的参数能得到相应的帮助信息
例子：
Help on built-in function raw_input in module __builtin__:
raw_input(...)
raw_input([prompt]) -> string
Read a string from standard input. The trailing newline is stripped.
If the user hits EOF (Unix: Ctl-D, Windows: Ctl-Z+Return), raise EOFError.
On Unix, GNU readline is used if enabled. The prompt string, if given,
is printed without a trailing newline before reading.
实现命令的小程序
import sys
def readfile(filename):
'''Print a file to the standard output.'''
f = file(filename)
while True:
line = f.readline()
if len(line) == 0:
break
print line,
f.close()
# Script starts from here
if len(sys.argv) < 2:
print 'No action specified.'
sys.exit()
if sys.argv[1].startswith('--'):
option = sys.argv[1][2:]
# fetch sys.argv[1] but without the first two characters
if option == 'version':
print 'Version 1.2'
elif option == 'help':
print '''"
This program prints files to the standard output.
Any number of files can be specified.
Options include:
--version : Prints the version number
--help : Display this help'''
else:
print 'Unknown option.'
sys.exit()
else:
for filename in sys.argv[1:]:
readfile(filename)
********************************************************************************************************************************
该程序能实现‘versioon“、”help“和读文件功能
命令：
[@zw_68_66 pythontest]# python new.py a.txt
hello word!
[@zw_68_66 pythontest]# python new.py --version
Version 1.2
[@zw_68_66 pythontest]# python new.py --help
"
This program prints files to the standard output.
Any number of files can be specified.
Options include:
--version : Prints the version number
--help : Display this help
*************************************************************************************************************************************