如何将数据框追加到excel工作表中

import pandas as pd
from openpyxl import load_workbook

# 读取现有Excel文件
existing_data = pd.read_excel('existing_data.xlsx')

# 创建新的数据框
new_data = pd.DataFrame({'Name': ['John', 'Emma', 'Michael'],
                         'Age': [25, 30, 35],
                         'City': ['New York', 'London', 'Tokyo']})

# 追加数据框
combined_data = pd.concat([existing_data, new_data])

# 将更新后的数据框写入Excel文件
writer = pd.ExcelWriter('combined_data.xlsx', engine='openpyxl')
writer.book = load_workbook('combined_data.xlsx')
combined_data.to_excel(writer, index=False, sheet_name='Sheet1')
writer.save()
writer.close()