使用python熊猫将现有的Excel工作表与新的数据框追加到新的数据框，而无需加载旧的

Question

This is an old question, however no one wrote a solution for without loading the excel file. Assuming the excel file is too huge, this will be inefficient to load the existing file and save on it. Instead is there any method to append, like for ordinary files?

df is the dataframe I would like to append

df.to_excel(folder+"file.xlsx", header=False, index=False)

However file.xlsx exists and there is another df with the same headers.

How can I append df to existing file.xlsx, without loading file.xlsx?

Answer 1

I do not know about any append features in Openpyxl. Openpyxl has however a writeonlymode wb = Workbook(write_only=True)

I would try to save (and append) the dataframe as a feather binary file, then just delete and create a new workbook with write_only mode.

This should be much faster than loading and appending the Excel file, but it will depend on what type and how much data there is.

Hope this helps.