def __init__(self, chunk_struct, debug_level=1):
        """
        Construct a new ``ChunkString`` that encodes the chunking of
        the text ``tagged_tokens``.

        :type chunk_struct: Tree
        :param chunk_struct: The chunk structure to be further chunked.
        :type debug_level: int
        :param debug_level: The level of debugging which should be
            applied to transformations on the ``ChunkString``.  The
            valid levels are:
                - 0: no checks
                - 1: full check on to_chunkstruct
                - 2: full check on to_chunkstruct and cursory check after
                   each transformation.
                - 3: full check on to_chunkstruct and full check after
                   each transformation.
            We recommend you use at least level 1.  You should
            probably use level 3 if you use any non-standard
            subclasses of ``RegexpChunkRule``.
        """
        self._root_label = chunk_struct.label()
        self._pieces = chunk_struct[:]
        tags = [self._tag(tok) for tok in self._pieces]
        self._str = '<' + '><'.join(tags) + '>'
        self._debug = debug_level
dataset/ETHPy150Open nltk/nltk/nltk/chunk/regexp.py/ChunkString.__init__/original