Python : parsing the command line options using optparse

[Ganesh Pal]

Hi Folks ,



Iam newbie to Python, Iam trying to use optparse module and write a script
that will parse the command line options ..I had to use opt parse instead
of argparse because by host Operating system is still using python 2.6


Below is the simple program ( Feel free to correct the error ) and 3 quick
questions on the same.


/* sample Program "/


import optparse



parser = optparse.OptionParser()



parser.add_option("-p", "--path", action="store",
metavar="/ifs/<file_name>|/ifs/<dir_name>", dest="path_name",

type="string",

help = "The file or directory path of the object in
/ifs",)



parser.add_option("-q", "--operation", action="store",
metavar="XOR|ADD|SET", dest="operation_type", default='SET',

type='choice', choices=['XOR', 'ADD', 'SET'],

help = "The corruption operation on the object [default :
%default]",)





parser.add_option("-f", "--offset", action="store", metavar="HEX",
dest="offset_value", default=0x41306141,

type="long",

help= "The valid offset value [default : %default]" )





parser.add_option("-n", "--node", action="store",metavar="id",
dest="node_value", default= 1,

type='int',

help = "The node id [default : %default]")



parser.add_option("-l", "--log", action="store_true",dest="log_file",

help = "log the isi_corrupt execution result ")



parser.add_option("-c", "--fixcrc", action="store_true",dest="fix_crc",

help = "The CRC fix of the corrupted objects ")



# instruct optparse to parse the program's command line:

(options, args) = parser.parse_args()



print options.path_name



Questions (1)


#python python-5.py --path=/ifs/1.txt --operation=XOR --node=11 --log
-fixcrc

line)


/ifs/1.txt


I wanted to store all the options in a list like
[/ifs/1.txt,XOR,11,log_file,fix_crc]

please suggest on the same ?







Question(2)



Why does this program work only with - option and not - in the above code
?



I think its not working when the type= 'choice' or its somethimf else ?


# python-5.py -p=/ifs/1.txt -q=XOR -f=1234 -n=1 -l

Usage: python-5.py [options]

python-5.py: error: option -q: invalid choice: '=XOR' (choose from 'XOR',
'ADD',

'SET', 'MODIFY', 'RENAME', 'DELETE', 'KILL')



This Works ( --)

C:\Users\bahadg\Desktop>python python-5.py --path=/ifs/1.txt
--operation=XOR --

offset=1234 --node=1 --log --fixcrc

/ifs/1.txt





Question (3)



If I have really long metavar and the help looks very messy ,is there a
way to make it look elegant.


Example :

parser.add_option("-q", "--operation", action="store",
metavar="XOR|ADD|SET|MODIFY|RENAME|DELETE|KILL|", dest="operation_type",
default='SET',

type='choice', choices=['XOR', 'ADD', 'SET'
|'MODIFY'|'RENAME'|'DELETE'|'KILL'],

help = "The corruption operation on the object [default :
%default]",)



#python-5.py --help



Usage: python-5.py [options]

Options:

-h, --help show this help message and exit

-p /ifs/<file_name>|/ifs/<dir_name>,
--path=/ifs/<file_name>|/ifs/<dir_name>

The file or directory path of the object in /ifs

-q XOR|ADD|SET|MODIFY|RENAME|DELETE|KILL|,
--operation=XOR|ADD|SET|MODIFY|RENA

ME|DELETE|KILL|

The corruption operation on the object [default :
SET]

-f HEX, --offset=HEX The valid offset value [default : 1093689665]

-n id, --node=id The node id [default : 1]

-l, --log log the isi_corrupt execution result

-c, --fixcrc The CRC fix of the corrupted objects





Thanks is advance !!