CrimeKgAssitant/crime_qa.py
2018-11-11 20:52:33 +08:00

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#!/usr/bin/env python3
# coding: utf-8
# File: crime_qa_server.py
# Author: lhy<lhy_in_blcu@126.com,https://huangyong.github.io>
# Date: 18-11-10
import os
import time
import json
from elasticsearch import Elasticsearch
import numpy as np
import jieba.posseg as pseg
class CrimeQA:
def __init__(self):
self._index = "crime_data"
self.es = Elasticsearch([{"host": "127.0.0.1", "port": 9200}])
self.doc_type = "crime"
cur = '/'.join(os.path.abspath(__file__).split('/')[:-1])
self.embedding_path = os.path.join(cur, 'embedding/word_vec_300.bin')
self.embdding_dict = self.load_embedding(self.embedding_path)
self.embedding_size = 300
self.min_score = 0.4
self.min_sim = 0.8
'''根据question进行事件的匹配查询'''
def search_specific(self, value, key="question"):
query_body = {
"query": {
"match": {
key: value,
}
}
}
searched = self.es.search(index=self._index, doc_type=self.doc_type, body=query_body, size=20)
# 输出查询到的结果
return searched["hits"]["hits"]
'''基于ES的问题查询'''
def search_es(self, question):
answers = []
res = self.search_specific(question)
for hit in res:
answer_dict = {}
answer_dict['score'] = hit['_score']
answer_dict['sim_question'] = hit['_source']['question']
answer_dict['answers'] = hit['_source']['answers'].split('\n')
answers.append(answer_dict)
return answers
'''加载词向量'''
def load_embedding(self, embedding_path):
embedding_dict = {}
count = 0
for line in open(embedding_path):
line = line.strip().split(' ')
if len(line) < 300:
continue
wd = line[0]
vector = np.array([float(i) for i in line[1:]])
embedding_dict[wd] = vector
count += 1
if count%10000 == 0:
print(count, 'loaded')
print('loaded %s word embedding, finished'%count, )
return embedding_dict
'''对文本进行分词处理'''
def seg_sent(self, s):
wds = [i.word for i in pseg.cut(s) if i.flag[0] not in ['x', 'u', 'c', 'p', 'm', 't']]
return wds
'''基于wordvector通过lookup table的方式找到句子的wordvector的表示'''
def rep_sentencevector(self, sentence, flag='seg'):
if flag == 'seg':
word_list = [i for i in sentence.split(' ') if i]
else:
word_list = self.seg_sent(sentence)
embedding = np.zeros(self.embedding_size)
sent_len = 0
for index, wd in enumerate(word_list):
if wd in self.embdding_dict:
embedding += self.embdding_dict.get(wd)
sent_len += 1
else:
continue
return embedding/sent_len
'''计算问句与库中问句的相似度,对候选结果加以二次筛选'''
def similarity_cosine(self, vector1, vector2):
cos1 = np.sum(vector1*vector2)
cos21 = np.sqrt(sum(vector1**2))
cos22 = np.sqrt(sum(vector2**2))
similarity = cos1/float(cos21*cos22)
if similarity == 'nan':
return 0
else:
return similarity
'''问答主函数'''
def search_main(self, question):
candi_answers = self.search_es(question)
question_vector = self.rep_sentencevector(question,flag='noseg')
answer_dict = {}
for indx, candi in enumerate(candi_answers):
candi_question = candi['sim_question']
score = candi['score']/100
candi_vector = self.rep_sentencevector(candi_question, flag='noseg')
sim = self.similarity_cosine(question_vector, candi_vector)
if sim < self.min_sim:
continue
final_score = (score + sim)/2
if final_score < self.min_score:
continue
answer_dict[indx] = final_score
if answer_dict:
answer_dict = sorted(answer_dict.items(), key=lambda asd:asd[1], reverse=True)
final_answer = candi_answers[answer_dict[0][0]]['answers']
else:
final_answer = '您好,对于此类问题,您可以咨询公安部门'
#
# for i in answer_dict:
# answer_indx = i[0]
# score = i[1]
# print(i, score, candi_answers[answer_indx])
# print('******'*6)
return final_answer
if __name__ == "__main__":
handler = CrimeQA()
while(1):
question = input('question:')
final_answer = handler.search_main(question)
print('answers:', final_answer)