code: def get_w605_position(tokens):
      
      # TODO: When this PR(*) change is released, use pos of pycodestyle
      # *: https://github.com/PyCQA/pycodestyle/pull/747
      valid = [
          '\n', '\\', '\'', '"', 'a', 'b', 'f', 'n', 'r', 't', 'v',
          '0', '1', '2', '3', '4', '5', '6', '7', 'x',
  
          # Escape sequences only recognized in string literals
          'N', 'u', 'U',
      ]
  
      for token_type, text, start_pos, _end_pos, _line in tokens:
          if token_type == tokenize.STRING:
              quote = text[-3:] if text[-3:] in ('"""', "'''") else text[-1]
              # Extract string modifiers (e.g. u or r)
              quote_pos = text.index(quote)
              prefix = text[:quote_pos].lower()
              start = quote_pos + len(quote)
              string = text[start:-len(quote)]
  
              if 'r' not in prefix:
                  pos = string.find('\\')
                  while pos >= 0:
                      pos += 1
                      if string[pos] not in valid:
                          yield (
                              # No need to search line, token stores position
                              start_pos[1],
                              "W605 invalid escape sequence '\\%s'" %
                              string[pos],
                          )
                      pos = string.find('\\', pos + 1)
docs: workaround get pointing out position by W605.