Wie füge ich einen Pandas-DataFrame an eine vorhandene Excel-Tabelle an, ohne Daten zu überschreiben?

appended_data.to_excel(os.path.join(newpath, 'master_data.xlsx'), sheet_name='Sheet1', mode='a', if_sheet_exists='overlay')

def append_df_to_excel(filename, df, sheet_name='Sheet1', startrow=None, **to_excel_kwargs):
    """
    Append a DataFrame [df] to existing Excel file [filename]
    into [sheet_name] Sheet.
    If [filename] doesn't exist, then this function will create it.
    """
    writer = pd.ExcelWriter(filename, engine='openpyxl', mode='a')
    if sheet_name in writer.book.sheetnames:
        # try to open an existing workbook
        writer.book = load_workbook(filename)
        # truncate sheet
        if startrow is None and sheet_name in writer.book.sheetnames:
            startrow = writer.book[sheet_name].max_row
        # index of [sheet_name] sheet
        idx = writer.book.sheetnames.index(sheet_name)
        # remove [sheet_name]
        writer.book.remove(writer.book.worksheets[idx])
        # create an empty sheet [sheet_name] using old index
        writer.book.create_sheet(sheet_name, idx)
        # copy existing sheets
        writer.sheets = {ws.title: ws for ws in writer.book.worksheets}
    else:
        # file doesn't exist, we are creating a new one
        startrow = 0
    # write out the DataFrame to an ExcelWriter
    df.to_excel(writer, sheet_name=sheet_name, **to_excel_kwargs)
    writer.close()
    writer.save()

appended_data.to_excel(os.path.join(newpath, 'master_data.xlsx'), sheet_name='Sheet1', mode='a', if_sheet_exists='overlay')

import pandas as pd

# Existing data
existing_df = pd.DataFrame({
    'Name': ['John', 'Mary', 'Bob'],
    'Age': [20, 25, 30]
})

# New data to append
new_df = pd.DataFrame({
    'Name': ['Alice', 'Tom'],
    'Age': [35, 40]
})

append_df_to_excel('master_data.xlsx', new_df, sheet_name='Sheet1', startrow=existing_df.shape[0] + 1)