python – Stream a huge Excel file, creating it on the fly?

I’m writing a web application that might sometimes output dozens of thousands of rows (or even more) in an Excel file. openpyxl was chosen for Excel output preparation, but I’m not sure if I could read the data from the database and output it at the same time. Is there a way to do that? Here’s an example of what I mean in CSV:

def csv_view(request, iterator, keys):
    """A view that streams a large CSV file."""

    class Echo(object):
        """An object that implements just the write method of the file-like
        interface.
        """
        def write(self, value):
            """Write the value by returning it,
               instead of storing in a buffer."""
            return value

    def get_iter():

        writer = csv.writer(Echo())
        yield writer.writerow(keys)
        for row in iterator:
            yield writer.writerow(row)

    response = StreamingHttpResponse(get_iter(), content_type="text/csv")
    response['Content-Disposition'] = 'attachment; filename="output.csv"'
    return response

Tags: excel, file, pythonpython