app.py

import streamlit as st
import torch
from sentence_transformers import SentenceTransformer, util

#使页面布局更宽
st.set_page_config(layout="wide")

def app():
    # 创建Streamlit应用程序

    st.title("对比句子的相似度")

    source_text = st.text_input("源句子", value="")

    st.write("待比较的句子：")

    if "inputs" not in st.session_state:
	    # 创建一个空列表来存储输入框列表
        st.session_state.inputs = []
        st.session_state.inputs_index = 0


    with st.container():
        # 在容器中渲染已经存在的输入框列表
        for i in range(0, st.session_state.inputs_index):
            st.session_state.inputs[i]= st.text_input(f"请输入第 {i+1} 个句子", "", key=i)

    # 创建一个添加输入框的按钮
    add_input_button = st.button("添加一个待比较句子")

	# 当用户点击按钮时往容器中添加新的输入框
    if add_input_button:
        i = st.session_state.inputs_index
        st.session_state.inputs.append(st.text_input(f"请输入第 {i+1} 个句子", "", key=i))
        # 自增输入框的key
        st.session_state.inputs_index += 1
    
    button_generate = st.button("计算")
    button_clear = st.button("清空")

    def transformer(source_text, sentences):
        #使用模型分别计算源字符串和对比字符串的embedding
        model = SentenceTransformer('sentence-transformers/paraphrase-multilingual-MiniLM-L12-v2', device="cpu")
        source_emb = model.encode(source_text, convert_to_tensor=True)
        sent_embs = model.encode(sentences, convert_to_tensor=True)
        #计算源字符串和对比字符串embedding的cos值
        cos_sim = util.cos_sim(source_emb, sent_embs)

        cosin_dict = {}

        for i, cos in enumerate(torch.flatten(cos_sim)):
            cosin_dict[sentences[i]] = cos
        
        #根据cos值降序排列
        sorted_dict = dict(sorted(cosin_dict.items(), key=lambda item: item[1],reverse = True))
        return sorted_dict


    if button_generate:
        # embeddings
        embeddings = transformer([source_text], st.session_state.inputs)

        # 显示对比的字符串、进度条、cos值
        with st.container():
            for sent, cos in embeddings.items():
                col1, col2, col3 = st.columns(3)
                cos_value = round(float(cos.item()),4)
                with col1:
                    st.text(sent)
                with col2:
                    bar = st.progress(cos_value)
                with col3:
                    st.text(cos_value)

    if button_clear:
        #清空对比字符串
        st.session_state.inputs.clear()
        del st.session_state["inputs"]
        st.session_state.inputs_index = 0
        source_text = ''
        st.experimental_rerun()

   

if __name__ == "__main__":
    # 运行应用程序
    app()