写一个python代码，在不修改原工作表第1，第2行内容的条件下，将dateframe从excel表格第3行开始覆盖到excel工作表之中，

答案：

import pandas as pdexcel_file = 'filename.xlsx'
df = pd.read_excel(excel_file, header=2)with pd.ExcelWriter(excel_file, engine='openpyxl', mode='w') as writer:
    writer.book = openpyxl.load_workbook(excel_file)
    writer.sheets = dict((ws.title, ws) for ws in writer.book.worksheets)
    df.to_excel(writer, sheet_name='Sheet1', index=False, header=False, startrow=2)
    writer.save()