python:将dataframe更新到现有的excel工作表，而不覆盖同一工作表和其他工作表上的内容。

import pandas as pd
from openpyxl import load_workbook

excel_file = 'path_to_excel_file.xlsx'
book = load_workbook(excel_file)
writer = pd.ExcelWriter(excel_file, engine='openpyxl') 
writer.book = book

sheet_name = 'existing_sheet_name'
existing_data = pd.read_excel(excel_file, sheet_name=sheet_name)

updated_data = pd.concat([existing_data, dataframe_to_update], ignore_index=True)

updated_data.to_excel(writer, sheet_name=sheet_name, index=False)

writer.save()
writer.close()