BadZipFile: File is not a zip file

使用openpyxl保存数据到Excel文件报错：BadZipFile: File is not a zip file

如果保存的文件不存在，直接用pd.ExcelWriter

如果保存的文件已存在，用openpyxl.load_workbook加载已有的文件, 再使用pd.ExcelWriter

如果pd.ExcelWriter和openpyxl.load_workbook的顺序反了，则报错：BadZipFile: File is not a zip file

def append2sheet(filename,data):
	
	if not os.path.exists(file_name):
		ew = pd.ExcelWriter(file_name)
		data.to_excel(ew,sheet_name = 'sheet1')
		ew.save()

	else:
		wb = load_workbook(file_name)
		ew = pd.ExcelWriter(file_name)
		ew.book = wb 
		data.to_excel(ew,sheet_name = 'new')
		ew.save()