python optparse, how to include additional info in usage output?

Question

Using python\'s optparse module I would like to add extra example lines below the regular usage output. My current help_print() output looks like this:

usage: ch         


        

Answer 1

Use the usage parameter:

usage = "usage: %prog [options] arg1 arg2"
parser = OptionParser(usage=usage)

You can add more through (just an example):

group = OptionGroup(parser, "Dangerous Options",
                    "Caution: use these options at your own risk.  "
                    "It is believed that some of them bite.")
group.add_option("-g", action="store_true", help="Group option.")
parser.add_option_group(group)

Example output:

usage: [options] arg1 arg2

options: -h, --help show this help message and exit
-v, --verbose make lots of noise [default]
-q, --quiet be vewwy quiet (I'm hunting wabbits)
-fFILE, --file=FILE write output to FILE
-mMODE, --mode=MODE interaction mode: one of 'novice', 'intermediate', [default], 'expert'

Dangerous Options: Caution: use of these options is at your own risk. It is believed that some of them bite. -g Group option.

Have a look here.