Django: openpyxl saving workbook as attachment

Question

Hi I have a quick question. I didn't find answer in internet maybe someone of you can help me.

So i want to save workbook as attachment but I don't know how lets see an example :

    from openpyxl import Workbook
    from openpyxl.cell import get_column_letter
    wb = Workbook(encoding='utf-8')
    dest_filename = 'file.xlsx'
    ws = wb.worksheets[0]
    ws.title = "range names"
    for col_idx in xrange(1, 40):
        col = get_column_letter(col_idx)
        for row in xrange(1, 600):
            ws.cell('%s%s'%(col, row)).value = '%s%s' % (col, row)
    ws = wb.create_sheet()
    ws.title = 'Pi'
    ws.cell('F5').value = 3.14

Then I tried :

response = HttpResponse(wb, content_type='application/vnd.ms-excel')
response['Content-Disposition'] = 'attachment; filename="foo.xls"'
return response

It's returning xlsx file indeed but in file there is only object adres not the content of file:

<openpyxl.workbook.Workbook object at 0x00000000042806D8>

Can someone help ?

Answer 1

Give it a try:

from openpyxl.writer.excel import save_virtual_workbook
...
response = HttpResponse(save_virtual_workbook(wb), content_type='application/vnd.ms-excel')

save_virtual_workbook was specially designed for your use case. Here's a docstring:

"""Return an in-memory workbook, suitable for a Django response."""

Answer 2

I usually use

ws = wb.add_sheet("Pi")

instead of

ws = wb.create_sheet()
ws.title = "Pi"

Moreover, you can try to do: (see documentation)

wb.save(stream)

and then use stream in HttpResponse.

Answer 3

On at least some versions of django/python/openpyxl, the given solution does not work. See https://bitbucket.org/openpyxl/openpyxl/issues/657/save_virtual_workbook-generates-junk-data

Simple working solution:

wb = Workbook(write_only=True, encoding='utf-8')
ws = wb.create_sheet()
for row in data:
    ws.append([str(cell) for cell in row])
response = HttpResponse(content_type='application/vnd.ms-excel')
wb.save(response)

What's happening here is that Django's HttpResponse is a file-like object. Workbook.save() can take a file-like object. (Internally, it uses zipfile, which takes either a filename or a file-like object.)

If you're manipulating the file in memory, this is the simplest and probably most efficient solution. A streaming response doesn't really make sense since the data is not being created with a generator. Even if save_virtual_workbook works, the data it writes is generated as a block before it's readable.

The other option would be to create a NamedTemporaryFile (from tempfile or Django's wrapper), pass that into Workbook.save(), then use FileResponse to stream that from the filesystem instead of from memory.