code: def yn_choice(message, default='y', tries=None):
      
      # http://stackoverflow.com/questions/3041986/python-command-line-yes-no-input"""
      choices = 'Y/n' if default.lower() in ('y', 'yes') else 'y/N'
      if tries is None:
          choice = input("%s (%s) " % (message, choices))
          values = ('y', 'yes', '') if default == 'y' else ('y', 'yes')
          return True if choice.strip().lower() in values else False
      else:
          while tries > 0:
              choice = input(
                  "%s (%s) (%s)" % (message, choices, "'q' to discard"))
              choice = choice.strip().lower()
              if choice in ['y', 'yes']:
                  return True
              elif choice in ['n', 'no', 'q']:
                  return False
              else:
                  print("Invalid input...")
                  tries -= 1
docs: asks for a yes/no question.
  
      :param tries: the number of tries
      :param message: the message containing the question
      :param default: the default answer