code: def css_unescape(content, string=False):
      
  
      def replace(m):
          """Replace with the appropriate substitute."""
  
          if m.group(1):
              codepoint = int(m.group(1)[1:], 16)
              if codepoint == 0:
                  codepoint = UNICODE_REPLACEMENT_CHAR
              value = util.uchr(codepoint)
          elif m.group(2):
              value = m.group(2)[1:]
          elif m.group(3):
              value = '\ufffd'
          else:
              value = ''
  
          return value
  
      return (RE_CSS_ESC if not string else RE_CSS_STR_ESC).sub(replace, content)
docs: Unescape CSS value.
  
      Strings allow for spanning the value on multiple strings by escaping a new line.