code: def str_on_2_unicode_on_3(s):
      
  
      if not PY3:
          return str(s)
      else:  # 3+
          if not isinstance(s, str):
              return str(s, encoding="utf-8")
          return s
docs: argparse is way too awesome when doing repr() on choices when printing usage
  
      :param s: str or unicode
      :return: str on 2, unicode on 3