code: def rpr(s):
      
      if s is None:
          return 'None'
      seen_unicode = False
      results = []
      for cc in s:
          ccn = ord(cc)
          if ccn >= 32 and ccn < 127:
              if cc == "'":  # escape single quote
                  results.append('\\')
                  results.append(cc)
              elif cc == "\\":  # escape backslash
                  results.append('\\')
                  results.append(cc)
              else:
                  results.append(cc)
          else:
              seen_unicode = True
              if ccn <= 0xFFFF:
                  results.append('\\u')
                  results.append("%04x" % ccn)
              else:  # pragma no cover
                  results.append('\\U')
                  results.append("%08x" % ccn)
      result = "'" + "".join(results) + "'"
      if seen_unicode:
          return "u(" + result + ")"
      else:
          return result
docs: Create a representation of a Unicode string that can be used in both
      Python 2 and Python 3k, allowing for use of the u() function