code: def _swap_curly(string):
      
      return (
          string.replace('{{ ', '{{').replace('{{', '\x00').replace('{', '{{')
          .replace('\x00', '{').replace(' }}', '}}').replace('}}', '\x00')
          .replace('}', '}}').replace('\x00', '}')
      )
docs: Swap single and double curly brackets