code: def _usage(prog_name=os.path.basename(sys.argv[0])):
      '''Returns usage string with no trailing whitespace.'''
      spacer = ' ' * len('usage: ')
      usage = prog_name + ' -b LIST [-S SEPARATOR] [file ...]\n' \
         + spacer + prog_name + ' -c LIST [-S SEPERATOR] [file ...]\n' \
         + spacer + prog_name \
         + ' -f LIST [-d DELIM] [-e] [-S SEPERATOR] [-s] [file ...]'
  
      # Return usage message with trailing whitespace removed.
      return "usage: " + usage.rstrip(f _usage(prog_name=os.path.basename(sys.argv[0])):
      '''Returns usage string with no trailing whitespace.'''
      spacer = ' ' * len('usage: ')
      usage = prog_name + ' -b LIST [-S SEPARATOR] [file ...]\n' \
         + spacer + prog_name + ' -c LIST [-S SEPERATOR] [file ...]\n' \
         + spacer + prog_name \
         + ' -f LIST [-d DELIM] [-e] [-S SEPERATOR] [-s] [file ...]'
  
      # Return usage message with trailing whitespace removed.
      return "usage: " + usage.rstrip()
docs: Returns usage string with no trailing whitespace.