code: def _generate_input(options):
      
      if options.input:
          fp = open(options.input) if options.input != "-" else sys.stdin
          for string in fp.readlines():
              yield string
      if options.strings:
          for string in options.strings:
              yield string
docs: First send strings from any given file, one string per line, sends
      any strings provided on the command line.
  
      :param options: ArgumentParser or equivalent to provide
          options.input and options.strings.
      :return: string