List dict

    def build_bloc(self):
        '''
        Build the principal bloc.
        '''

        self._p_list = []
        self._assossiated_list = {}

        tmp_list = list()
        tag_class = defaultdict(dict)
        tag_dict = defaultdict(dict)

        def get_astd(tag):
            rgx = re.compile(r"xml-(\w+)")
            if 'class' in tag.attrib:
                logging.info(tag.attrib['class'])
                try:
                    logging.info('Checking if had many value')
                    if tag.attrib['class'].split(' ')[1]:
                        logging.info('Ok it has')
                        for t in tag.attrib['class'].split(' '):
                            logging.info(t)
                            logging.info('Lauching the matching process')
                            srch_res = re.match(rgx, t)
                            logging.debug('srch_res : '+str(srch_res))
                            if srch_res is not None:

                                logging.info('Match !')

                                # Source : http://stackoverflow.com/a/12906014/5527968
                                tag_class = (tag.attrib['class'].split(' ')[0])
                                tag_dict[srch_res.group(1)][tag.tag] = [tag_class]
                                logging.info('tag_dict : ')
                                logging.info(pprint.pprint(tag_dict))

                                #self._assossiated_list.setdefault(srch_res.group(1), {})[tag.tag] = tag_class
                            else:
                                continue
                    else:
                        pass

                except Exception as e:
                    logging.info(e)
                    pass

                logging.info(tmp_list)

        def find_xml_tag():
            logging.info('Find all xml-tag')
            self._p_list = self._tree.xpath('//*') # For all existing tag
            for p in self._p_list:
                get_astd(p)

        find_xml_tag()
        logging.info(pprint.pprint(self._assossiated_list))

# Expected output :
# {'caption': {'p': ['Citation', 'Ct']},
# 'chapter': {'head': 'Chapter'},
# 'niv1': {'h2': 'Stitre1', 'p': 'Stitre1'},
# 'niv2': {'h3': 'Stitre2'}}

# Ouput :
# {'caption': {'p': 'Citation'},
# 'chapter': {'head': 'Chapter'},
# 'niv1': {'h2': 'Stitre1', 'p': 'Stitre1'},
# 'niv2': {'h3': 'Stitre2'}}