domtree2data.py

# -*- coding: utf-8 -*-

"""
@author: taoqi
@file: domtree2data.py
@time: 2019-07-03 14:47
"""


class Converter:
    def __init__(self, dom_tree, dimension):
        self.dom_tree = dom_tree
        self.node_info_list = []
        self.dimension = dimension
        self.initial_weight = 1
        self.attenuation_ratio = 0.6
        self.dom_eigenvector = {}.fromkeys(range(0, dimension), 0)

    def get_eigenvector(self):
        for node_id in range(1, self.dom_tree.size() + 1):
            node = self.dom_tree.get_node(node_id)
            node_feature = self.create_feature(node)
            feature_hash = self.feature_hash(node_feature)
            node_weight = self.calculate_weight(node, node_id, feature_hash)
            self.construct_eigenvector(feature_hash, node_weight)
        return self.dom_eigenvector

    @staticmethod
    def create_feature(node):
        node_attr_list = []
        node_feature = node.data.label + '|'
        for attr in node.data.attrs.keys():
            node_attr_list.append(attr + ':' + str(node.data.attrs[attr]))
        node_feature += '|'.join(node_attr_list)
        return node_feature

    @staticmethod
    def feature_hash(node_feature):
        return abs(hash(node_feature)) % (10 ** 8)

    def calculate_weight(self, node, node_id, feature_hash):
        brother_node_count = 0
        depth = self.dom_tree.depth(node)
        for brother_node in self.dom_tree.siblings(node_id):
            brother_node_feature_hash = self.feature_hash(self.create_feature(brother_node))
            if brother_node_feature_hash == feature_hash:
                brother_node_count = brother_node_count + 1
        if brother_node_count:
            node_weight = self.initial_weight * self.attenuation_ratio ** depth * self.attenuation_ratio ** brother_node_count
        else:
            node_weight = self.initial_weight * self.attenuation_ratio ** depth
        return node_weight

    def construct_eigenvector(self, feature_hash, node_weight):
        feature_hash = feature_hash % self.dimension
        self.dom_eigenvector[feature_hash] += node_weight