openpyxl更新后如何将数据框附加到现有的excel工作表（不覆盖它）？

Question

我有一个现有的 excel 文件，我必须每周用新数据更新它，并将其附加到现有工作表的最后一行。按照这篇文章How to write to an existing excel file without overwriting data (using pandas)?中提供的解决方案，我以这种方式完成了这项工作@

import pandas as pd
import openpyxl
from openpyxl import load_workbook

book = load_workbook(excel_path)
writer = pd.ExcelWriter(excel_path, engine = 'openpyxl',  mode = 'a')
writer.book = book

## ExcelWriter for some reason uses writer.sheets to access the sheet.
## If you leave it empty it will not know that sheet Main is already there
## and will create a new sheet.
ws = book.worksheets[1]
writer.sheets = dict((ws.title, ws) for ws in book.worksheets)

df.to_excel(writer, 'Preço_por_quilo', startrow = len(ws["C"]), header = False, index = False)

writer.save()
writer.close()

这段代码运行正常，直到今天，它返回以下错误：

ValueError: Sheet 'Preço_por_quilo' already exists and if_sheet_exists is set to 'error'.

这显然是由 openpyxl 包的最新更新产生的，它向 ExcelWriter 函数添加了“if_sheet_exists”参数。 如何更正此代码，以便将我的数据附加到工作表的最后一行？

Answer 1

将if_sheet_exists=replace 添加到df.to_excel 的末尾应该可以，如下所示：

df.to_excel(writer, 'Preço_por_quilo', startrow = len(ws["C"]), header = False, index = False, if_sheet_exists='replace')

更多关于它的使用信息可以在这里找到： https://pandas.pydata.org/docs/reference/api/pandas.ExcelWriter.html