Optparse to parsing Suggestions !!

[Ganesh Pal]

Hello Python world ,


I wanted suggestion on how to modify the below code to help me accomodate
the below two cases

# Here is the Sample code.

def main():
""" ---MAIN--- """
parser = optparse.OptionParser(usage='%prog [options] <arg1>.]',
version='1.0')
object_choice = ('super_block','blocks''files', 'directory','links')

parser.add_option("-o", "--object",
action="store",metavar="object",default='inode',dest="object",type='choice',
choices=object_choice,
help='The object type to be corrupted [ choose from ('
+ ','.join(object_choice) + ') default: %default]',)

parser.add_option("-p",
"--path",action="store",metavar="/mnt/",dest="path",type="string",help="The
file or directory path in /mnt/",)

parser.add_option("-n",
"--size",action="store",metavar="size",dest="size",default=1,type='int',help="The
offset field)


# Instruct optparse to parse the program's command line:
(options, args) = parser.parse_args()

# Build the dispatch table:
object_type_dictionary = {
"super_block":super_block_def,
"blocks":blocks_def,
"files": files_corrupt_def,
"directory": directory_corrupt_def,
"links": links_corrput_def, # no () here,we're storing function
}

# Lookup the object type and then call the function:
object_type_dictionary[options.object]()


Sample Run
# python corrupt.py --object=files --path=/tmp/ --size 1000


Questions :

Case 1: # The --path is optional for few for the object type. How do I
simulate the below behaviour

#python corrupt.py --object=super_block --size=1000

==> Should work even if --path is not given

#python corrupt.py --object=super_block --path=/tmp/--size 1000

==> If user enters --object=super_block and --path=/ifs/ should
throw an error

saying its an invaild combinations.



case 2: # The --path is mandatory for few of the object types and should
complain if its not entered .

# python corrupt.py --object=files --path=/tmp/ --size 1000



Regards,
Ganesh