code: def convert_parens_in_rst_tree_str(rst_tree_str):
      '''
      This converts '(' and ')' brackets the EDUs of the RST into PTB-style
      tokens (e.g., -LRB-) to escape them for nltk.
      '''
      def replace_brackets(matchobj):
          edu = matchobj.group(0)
          for (br, br_repl) in DIS_ESCAPES:
              edu = re.sub("\{}".format(br), br_repl, edu)
          return edu
  
      return re.sub('_!(.*?)_!', replace_brackets, rst_tree_strf convert_parens_in_rst_tree_str(rst_tree_str):
      '''
      This converts '(' and ')' brackets the EDUs of the RST into PTB-style
      tokens (e.g., -LRB-) to escape them for nltk.
      '''
      def replace_brackets(matchobj):
          edu = matchobj.group(0)
          for (br, br_repl) in DIS_ESCAPES:
              edu = re.sub("\{}".format(br), br_repl, edu)
          return edu
  
      return re.sub('_!(.*?)_!', replace_brackets, rst_tree_str)
docs: This converts '(' and ')' brackets the EDUs of the RST into PTB-style
      tokens (e.g., -LRB-) to escape them for nltk.