app.py

from langchain.embeddings import OpenAIEmbeddings
from langchain.vectorstores import Chroma
from langchain.llms import OpenAI
from langchain.chains.question_answering import load_qa_chain
import os
import fitz
import re
import gradio as gr






def preprocess(text):
    text = text.replace('\n', '')
    return text

def pdf_to_text(path, start_page=1, end_page=None):
    doc = fitz.open(path)
    total_pages = doc.page_count

    if end_page is None:
        end_page = total_pages

    text_list = []

    for i in range(start_page - 1, end_page):
        text = doc.load_page(i).get_text("text")
        text_list.append(text)

    doc.close()
    return text_list

def law_split(path,name):
    text_list=pdf_to_text(path)
    text= ''.join(text_list)
    text_split=re.split(r'第.+条\s',text)[1:]

    for index, text in enumerate(text_split):
        text=preprocess(text)
        text_split[index]=f'《中华人民共和国{name}》 第{index+1}条 '+text
    
    return text_split


def folder_read(path):
    text_list=[]
    paths=os.listdir(path)
    for file in paths:
        name=file.split('.')[0]
        suffix=file.split('.')[-1]
        if suffix=='pdf':
            text_list+=law_split(f'{path}/{file}',name)
        
        
    return text_list


text_list=folder_read('laws')
embeddings = OpenAIEmbeddings()
vectordb = Chroma.from_texts(texts=text_list, embedding=embeddings)
llm = OpenAI(temperature=0.5,max_tokens=1024)



def generate_answer(question):
    prompt='''
    请根据给出的法律条文回答问题，给出适当的法律建议。回答时要说出你引用的法律条文是第几条，并说出引用的每一条是哪部法律中的。
    引用的法律条文不要超过两条，回答尽量简明扼要
    如果问题与搜索结果无关，就仅回答"该问题与青少年法律无关"即可。
    '''
    most_relevant_texts = vectordb.max_marginal_relevance_search(question, k=5)
    chain = load_qa_chain(llm)
    answer = chain.run(input_documents=most_relevant_texts, question=question+prompt)
    return answer
    
def ask_api(question):
    
    if question.strip() == '':
        return '[ERROR]: 未输入问题'

    return generate_answer(question)



title = '青少年法律科普问答'
description = """ 本bot旨在根据中华人民共和国的法律回答有关青少年的问题，目前囊括的法律有\n
《未成年人保护法》\n
《义务教育法》\n
《预防未成年人犯罪法》\n
《妇女儿童权益保护法》
"""

print('test start')
print(generate_answer('未成年遭受网络欺凌该怎么办？'))
print('test end')


demo = gr.Interface(
    title=title,
    description=description,
    fn=ask_api, 
    inputs=gr.Textbox(label="请输入与青少年法律相关的问题",lines=2), 
    outputs=gr.outputs.Textbox(label="参考回答"), 
    examples=[["未成年遭受网络欺凌该怎么办？"],['年满多少岁的儿童应当接受义务教育？'],['若发现离家出走的未成年人，应如何处理？']])


demo.launch()