[知识图谱]利用py2neo从Neo4j数据库获取数据 

  1 # -*- coding: utf-8 -*-
  2 
  3 from py2neo import Graph
  4 import json
  5 import re
  6 
  7 
  8 class Neo4jToJson(object):
  9     """知识图谱数据接口"""
 10 
 11     def __init__(self):
 12         """初始化数据"""
 13         # 与neo4j服务器建立连接
 14         self.graph = Graph("http://IP//:7474", username="neo4j", password="xxxxx")
 15         self.links = []
 16         self.nodes = []
 17 
 18     def post(self):
 19         """与前端交互"""
 20         # 前端传过来的数据
 21         select_name = '南京审计大学'
 22         # 取出所有节点数据
 23         nodes_data_all = self.graph.run("MATCH (n) RETURN n").data()
 24         # node名存储
 25         nodes_list = []
 26         for node in nodes_data_all:
 27             nodes_list.append(node['n']['name'])
 28         # 根据前端的数据，判断搜索的关键字是否在nodes_list中存在，如果存在返回相应数据，否则返回全部数据
 29         if select_name in nodes_list:
 30             # 获取知识图谱中相关节点数据
 31             nodes_data = self.graph.run("MATCH (n)--(b) where n.name='" + select_name + "' return n,b").data()
 32             links_data = self.graph.run("MATCH (n)-[r]-(b) where n.name='" + select_name + "' return r").data()
 33             self.get_select_nodes(nodes_data)
 34         else:
 35             # 获取知识图谱中所有节点数据
 36             links_data = self.graph.run("MATCH ()-[r]->() RETURN r").data()
 37             nodes_data = self.graph.run("MATCH (n) RETURN n").data()
 38             self.get_all_nodes(nodes_data)
 39 
 40         self.get_links(links_data)
 41 
 42         # 数据格式转换
 43         neo4j_data = {'links': self.links, 'nodes': self.nodes}
 44         neo4j_data_json = json.dumps(neo4j_data, ensure_ascii=False).replace(u'\xa0', u'')
 45         return neo4j_data_json
 46 
 47     def get_links(self, links_data):
 48         """知识图谱关系数据获取"""
 49         links_data_str = str(links_data)
 50         links = []
 51         i = 1
 52         dict = {}
 53         # 正则匹配
 54         links_str = re.sub("[\!\%\[\]\,\。\{\}\-\:\'\(\)\>]", " ", links_data_str).split(' ')
 55         for link in links_str:
 56             if len(link) > 1:
 57                 if i == 1:
 58                     dict['source'] = link
 59                 elif i == 2:
 60                     dict['name'] = link
 61                 elif i == 3:
 62                     dict['target'] = link
 63                     self.links.append(dict)
 64                     dict = {}
 65                     i = 0
 66                 i += 1
 67         return self.links
 68 
 69     def get_select_nodes(self, nodes_data):
 70         """获取知识图谱中所选择的节点数据"""
 71         dict_node = {}
 72         for node in nodes_data:
 73             name = node['n']['name']
 74             tag = node['n']['tag']
 75             dict_node['name'] = name
 76             dict_node['tag'] = tag
 77             self.nodes.append(dict_node)
 78             dict_node = {}
 79             break
 80         for node in nodes_data:
 81             name = node['b']['name']
 82             tag = node['b']['tag']
 83             dict_node['name'] = name
 84             dict_node['tag'] = tag
 85             self.nodes.append(dict_node)
 86             dict_node = {}
 87 
 88     def get_all_nodes(self, nodes_data):
 89         """获取知识图谱中所有节点数据"""
 90         dict_node = {}
 91         for node in nodes_data:
 92             name = node['n']['name']
 93             tag = node['n']['tag']
 94             dict_node['name'] = name
 95             dict_node['tag'] = tag
 96             self.nodes.append(dict_node)
 97             dict_node = {}
 98         return self.nodes
 99 
100 
101 
102 if __name__ == '__main__':
103     data_neo4j = Neo4jToJson()
104     print(data_neo4j.post())

 

posted @ 2018-11-07 10:56  王马扎  阅读(5487)  评论(0)  编辑  收藏  举报