知识图谱构建7——基于REFO的简单知识问答（KBQA）
实例结构：
- 利用get_dict.sh脚本将数据库电影名和演员名抽取出来，生成字典文件，用于扩展jieba分词，脚本一些命令可以参考：
shell教程：
http://www.runoob.com/linux/linux-shell-io-redirections.html
博客：命令行数据科学工具笔记
https://blog.imfing.com/2018/01/30/data-science-at-the-command-line
get_dict.sh脚本为：
#!/bin/bash
#连接MySQL数据库
Host=127.0.0.1（或者数据库服务器地址）
User=root
PW=数据库密码
#本地连接
mysql -u$User -p$PW <<EOF #开始SQL语句
use kg_movie;#选择数据库（选择模式）
#show tables;#执行SQL语句
select actor_chName from actor into outfile 'C:/ProgramData/MySQL/MySQL Server 5.7/Uploads/actor_Name.txt';
select movie_chName from movie into outfile 'C:/ProgramData/MySQL/MySQL Server 5.7/Uploads/movie_Name.txt';
EOF #结束SQL语句
# Append "nz" and "nr" tag for jieba
# nr代表演员名
# nz代表电影名称
awk '{print $0 " nr"}' actor_Name.txt > actorName.txt
awk '{print $0 " nz"}' movie_Name.txt > movieName.txt
# 移动文件夹到G:\PyCharmWP\kgMovie\KBQA\patternREFO\data
mv actorName.txt G:/PyCharmWP/kgMovie/KBQA/patternREFO/data/
mv movieName.txt G:/PyCharmWP/kgMovie/KBQA/patternREFO/data/
# Remove redundant file,actor_Name.txt and movieName.txt
rm *_Name.txt
# 注：将get_dict.sh 放到C:/ProgramData/MySQL/MySQL Server 5.7/Uploads目录下运行
将数据库中的字段数据导出时出现如下secure-file-priv选项问题：
ERROR 1290 (HY000) at line 4: The MySQL server is running with the --secure-file-priv option so it cannot execute this statement
参考：mysql5.7导出数据提示–secure-file-priv选项问题的解决方法
https://blog.csdn.net/fdipzone/article/details/78634992
- 利用jieba分词对中文句子进行分词和词性标注
关于jieba可以参考：
结巴中文分词：https://github.com/fxsjy/jieba
Python第三方库jieba（中文分词）入门与进阶（官方文档）
word_tagging.py:
# encoding=utf-8
import jieba
import jieba.posseg as pseg
class Word(object):
def __init__(self, token, pos):
self.token = token
self.pos = pos
class Tagger:
def __init__(self, dict_paths):
# TODO 加载外部词典
for p in dict_paths:
jieba.load_userdict(p)
@staticmethod
def get_word_objects(sentence):
# type: (str) -> list
"""
把自然语言转为Word对象
:param sentence:
:return:
"""
return [Word(word.encode('utf-8'), tag) for word, tag in pseg.cut(sentence)]
# TODO 用于测试
if __name__ == '__main__':
tagger = Tagger(['../data/actorName.txt', '../data/movieName.txt'])
while True:
print("请输入：")
s = input()
p = tagger.get_word_objects(s)
# print(p)
for i in tagger.get_word_objects(s):
print(i.token.decode('utf8'), i.pos)
# 测试结果：
# 请输入：
# 周星驰是谁
# 周星驰 nr
# 是 v
# 谁 r
- 将自然语言转换为SPARQL模板
rules.py:
#!/usr/bin/env python
# coding=utf-8
# 设置问题模板，为每个模板设置对应的SPARQL语句
import re
# SPARQL config
from refo.refo import Predicate, finditer, Star, Any
SPARQL_PREAMBLE = u"""
PREFIX : <http://www.kg_movie.com#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
"""
SPARQL_TEM = u"{preamble}\n" + \
u"SELECT DISTINCT {select} WHERE {
{\n" + \
u"{expression}\n" + \
u"}}\n"
INDENT = " "
class W(Predicate):
"""object-oriented regex for words"""
def __init__(self, token=".*", pos=".*"):
self.token = re.compile(token + "$")
self.pos = re.compile(pos + "$")
super(W, self).__init__(self.match)
def match(self, word):
# m1要将字节转化为字符串
m1 = self.token.match(word.token.decode('utf-8'))
m2 = self.pos.match(word.pos)
return m1 and m2
class Rule(object):
def __init__(self, condition=None, action=None):
assert condition and action
self.condition = condition
self.action = action
def apply(self, sentence):
matches = []
for m in finditer(self.condition, sentence):
i, j = m.span()
matches.extend(sentence[i:j])
if __name__ == '__main__':
pass
return self.action(matches)
# 某人是谁的问题
def who_is_question(x):
select = u"?x0"
sparql = None
for w in x:
if w.pos == "nr" or w.pos == "x":
e = u" ?a :actor_chName '{person}'. \n \
?a :actor_bio ?x0".format(person=w.token.decode("utf-8"))
sparql = SPARQL_TEM.format(preamble=SPARQL_PREAMBLE,
select=select,
expression=INDENT + e)
break
return sparql
# 某人来自哪里的问题
def where_is_from_question(x):
select = u"?x0"
sparql = None
for w in x:
if w.pos == "nr" or w.pos == "x" or w.pos == "nrt":
e = u" ?a :actor_chName '{person}'.\n \
?a :actor_birthPlace ?x0".format(person=w.token.decode("utf-8"))
sparql = SPARQL_TEM.format(preamble=SPARQL_PREAMBLE,
select=select,
expression=INDENT + e)
break
return sparql
# 某个电影简介的问题
def movie_intro_question(x):
select = u"?x0"
sparql = None
for w in x:
if w.pos == "nz":
e = u" ?a :movie_chName '{person}'. \n \
?a :movie_bio ?x0".format(person=w.token.decode("utf-8"))
sparql = SPARQL_TEM.format(preamble=SPARQL_PREAMBLE,
select=select,
expression=INDENT + e)
break
return sparql
def customize_rules():
# some rules for matching
# TODO: customize your own rules here
person = (W(pos="nr") | W(pos="x") | W(pos="nrt") | W(pos="nz"))
movie = (W(pos="nz"))
place = (W("出生地") | W("出生"))
intro = (W("简介") | W(pos="介绍"))
rules = [
Rule(condition=W(pos="r") + W("是") + person | \
person + W("是") + W(pos="r"),
action=who_is_question),
Rule(condition=person + Star(Any(), greedy=False) + place + Star(Any(), greedy=False),
action=where_is_from_question),
Rule(condition=movie + Star(Any(), greedy=False) + intro + Star(Any(), greedy=False),
action=movie_intro_question)
]
return rules
- 主程序
query.py:
#!/usr/bin/env python
# coding=utf-8
from SPARQLWrapper import SPARQLWrapper, JSON
from kgMovie.KBQA.patternREFO.utils.rules import customize_rules
from kgMovie.KBQA.patternREFO.utils.word_tagging import Tagger
if __name__ == "__main__":
print("init...........")
# 连接TDB数据库
sparql_base = SPARQLWrapper("http://localhost:3030/kg_movie/query")
# 加载外部词典
tagger = Tagger(['data/actorName.txt', 'data/movieName.txt'])
# 初始化并获取规则列表
rules = customize_rules()
print("done \n")
while True:
# 输入问题
print("Please input your question: ")
default_question = input()
# 获取wordclass
seg_list = tagger.get_word_objects(default_question)
for rule in rules:
# 将规则列表应用到问题上得到查询模板
query = rule.apply(seg_list)
if query:
# 设置查询相关
sparql_base.setQuery(query)
sparql_base.setReturnFormat(JSON)
# 得到返回结果并做转换
results = sparql_base.query().convert()
if not results["results"]["bindings"]:
print("No answer found :(")
continue
for result in results["results"]["bindings"]:
print("Result: ", result["x0"]["value"])
在运行query.py:前，应按照前面的教程将电影类知识图谱导入到Jena的TDB数据库中，并运行fuseki服务器，这样我们才能进行访问查询。
具体可见：知识图谱构建5——Jena 和 Fuseki安装与SPARQL查询
- 结果：
3个模板，3个问题
附： - 下载refo库进行安装
https://github.com/machinalis/refo
python setup.py install
- 出现错误：
TypeError: cannot use a string pattern on a bytes-like object
解决：m1要将字节转化为字符串
python2 和python3不兼容
参考：
[1]参考浙江大学在openKG上提供的 基于REfO的KBQA实现及示例
[2]从零开始构建知识图谱（三）基于REfO的简单知识问答
[3]电影知识图谱问答系统项目总结