new_contents: # -*- coding: utf-8 -*-
  from __future__ import absolute_import, unicode_literals
  import unittest
  
  from nltk import RegexpParser
  
  class TestChunkRule(unittest.TestCase):
  
      def test_tag_pattern2re_pattern_quantifier(self):
          """Test for bug https://github.com/nltk/nltk/issues/1597
      
          Ensures that curly bracket quantifiers can be used inside a chunk rule.
          This type of quantifier has been used for the supplementary example
          in http://www.nltk.org/book/ch07.html#exploring-text-corpora.
          """    
          sent = [('The', 'AT'), ('September-October', 'NP'), ('term', 'NN'), ('jury', 'NN'), ('had', 'HVD'), ('been', 'BEN'), ('charged', 'VBN'), ('by', 'IN'), ('Fulton', 'NP-TL'), ('Superior', 'JJ-TL'), ('Court', 'NN-TL'), ('Judge', 'NN-TL'), ('Durwood', 'NP'), ('Pye', 'NP'), ('to', 'TO'), ('investigate', 'VB'), ('reports', 'NNS'), ('of', 'IN'), ('possible', 'JJ'), ('``', '``'), ('irregularities', 'NNS'), ("''", "''"), ('in', 'IN'), ('the', 'AT'), ('hard-fought', 'JJ'), ('primary', 'NN'), ('which', 'WDT'), ('was', 'BEDZ'), ('won', 'VBN'), ('by', 'IN'), ('Mayor-nominate', 'NN-TL'), ('Ivan', 'NP'), ('Allen', 'NP'), ('Jr.', 'NP'), ('.', '.')] # source: brown corpus
          cp = RegexpParser('CHUNK: {<N.*>{4,}}')
          tree = cp.parse(sent)
          assert tree.pformat() == """(S
    The/AT
    September-October/NP
    term/NN
    jury/NN
    had/HVD
    been/BEN
    charged/VBN
    by/IN
    Fulton/NP-TL
    Superior/JJ-TL
    (CHUNK Court/NN-TL Judge/NN-TL Durwood/NP Pye/NP)
    to/TO
    investigate/VB
    reports/NNS
    of/IN
    possible/JJ
    ``/``
    irregularities/NNS
    ''/''
    in/IN
    the/AT
    hard-fought/JJ
    primary/NN
    which/WDT
    was/BEDZ
    won/VBN
    by/IN
    (CHUNK Mayor-nominate/NN-TL Ivan/NP Allen/NP Jr./NP)
    ./.)"""
  
  
subject: Fix 1597. Allow for curly bracket quantifiers in nltk.chunk.regexp.CHUNK_TAG_PATTERN.