Is it possible to make an option in optparse a mandatory?

Solution

I posted a comment earlier, but given that many other answers say No, not possible, here is how to do it:

parser = OptionParser(usage='usage: %prog [options] arguments')
parser.add_option('-f', '--file', 
                        dest='filename',
                        help='foo help')
(options, args) = parser.parse_args()
if options.filename is None:   # if filename is not given
    parser.error('Filename not given')

This makes the -f as mandatory.

Using argparse is an alternative indeed, but that doesn't mean you can't do this in optparse also.