code: def _compile_template_re(delimiters):
      
      # The possible tag type characters following the opening tag,
      # excluding "=" and "{".
      tag_types = "!>&/#^"
  
      # TODO: are we following this in the spec?
      #
      #   The tag's content MUST be a non-whitespace character sequence
      #   NOT containing the current closing delimiter.
      #
      tag = r"""
          (?P<whitespace>[\ \t]*)
          %(otag)s \s*
          (?:
            (?P<change>=) \s* (?P<delims>.+?)   \s* = |
            (?P<raw>{)    \s* (?P<raw_name>.+?) \s* } |
            (?P<tag>[%(tag_types)s]?)  \s* (?P<tag_key>[\s\S]+?)
          )
          \s* %(ctag)s
      """ % {'tag_types': tag_types, 'otag': re.escape(delimiters[0]), 'ctag': re.escape(delimiters[1])}
  
      return re.compile(tag, re.VERBOSE)
docs: Return a regular expression object (re.RegexObject) instance.