Copying data in excel - openpyxl

Question

I use the code fragment below to copy data to an excel file using openpyxl.

      for i, j in enumerate(fint):
       _= ws1.cell(column=i +1, row=globdat.cycle, value=j)

   wb.save(filename = dest_filename)

BUT

after doing so I have found the code to become very slow. is there a better way of doing this ?

globdat.cycle is a count for each iteration.

'fint' is a row vector with an unknown number of entries in each iteration.

Nb- I am working with large amounts of data so only openpyxl seem to work.

Answer 1

Unfortunately, due to the way data is stored in Excel it's quite difficult to do copy operations. The xlutils library does include some functions designed specifically for this but I don't know if they work for xlsx files.

If you just want part of the data then I would suggest that you open the file to copy from in read-only mode and write to another one in write-only mode. This will keep memory use down and should be pretty fast.

For other situations there were some suggestions made on the bug tracker: https://bitbucket.org/openpyxl/openpyxl/issue/171/