app.py

import streamlit as st
import base64
import unicodedata
import diff_match_patch as dmp_module
from enum import Enum

class Action(Enum):
    INSERTION = 1
    DELETION = -1
    EQUAL = 0

def compare_string(text1:str, text2: str) -> list:
    text1Normalized = unicodedata.normalize("NFKC", text1)
    text2Normalized = unicodedata.normalize("NFKC", text2)

    dmp = dmp_module.diff_match_patch()
    diff = dmp.diff_main(text1Normalized, text2Normalized)
    dmp.diff_cleanupSemantic(diff)

    return diff

def style_text(diff):
    fullText=""
    for action, text in diff:
        if action == Action.INSERTION.value:
            fullText += f"<span style='background-color:Lightgreen'>{text}</span>"
        elif action == Action.DELETION.value:
            fullText += f"<span style='background-color:#FFCCCB'><s>{text}</s></span>"
        elif action == Action.EQUAL.value:
            fullText += f"{text}"
        else:
            raise Exception("Not Implemented")
    fullText = fullText.replace('](', ']\(').replace('~', '\~')
    return fullText


if __name__=="__main__":

    col1, col2 = st.columns(2)
    with col1:
        text1 = st.text_area("Input Text", value=
        """The quick brown fox jumps over the lazy dog. この竹垣に竹立てかけたのは竹立てかけたかったからか竹立てかけ"""
        )
    with col2:
        text2 = st.text_area("Source Text", value=
        """The quick brown fox jumps over the lazy cat. この竹垣に竹立てかけたのは竹立てかけたかったから竹立てかけた"""
        )

    diff = compare_string(text2, text1)
    fullText = style_text(diff)
    st.markdown("<span style='background-color:#FFCCCB'><s>削除</s></span> <span style='background-color:Lightgreen'>追加</span>", unsafe_allow_html=True)
    st.markdown(fullText, unsafe_allow_html=True)