如何使用Python的optparse格式化位置参数帮助？

import optparse

def main():
    parser = optparse.OptionParser()
    parser.add_option("-f", "--file", dest="filename", help="write report to FILE", metavar="FILE")
    parser.add_option("-q", "--quiet", action="store_false", dest="verbose", default=True, help="don't print status messages to stdout")

    (options, args) = parser.parse_args()

    if options.verbose:
        print("Hello, world.")

if __name__ == "__main__":
    main()

python example.py -f filename.txt -q

python example.py --help

Usage: example.py [options]

Options:
  -h, --help            show this help message and exit
  -f FILE, --file=FILE  write report to FILE
  -q, --quiet            don't print status messages to stdout