from dials.util.options import OptionParser parser = OptionParser(usage="usage: %prog [options] arg1 arg2", description="This program does something useful", epilog="Thanks for using this program!") parser.add_option("-f", "--file", dest="filename", help="specify the name of the input file") parser.add_option("-v", "--verbose", action="store_true", dest="verbose", default=False, help="print detailed output") (options, args) = parser.parse_args() if options.filename: process_file(options.filename, options.verbose) else: print("Please specify an input file.")In this example, the program defines a parser object, specifies the usage and description information, and declares two options: '-f' or '--file' for specifying the input file name, and '-v' or '--verbose' for enabling verbose output. The options are then parsed from the command line using the parse_args method, and the input file is processed accordingly. This code example is part of the DIALS (Diffraction Integration for Advanced Light Sources) package library, which provides software for processing X-ray diffraction data.