Output an XLS file with XLWT

Render_to_XLS.py

from django.template import Variable, defaultfilters
from django.http import HttpResponse
import xlwt

def render_to_xls(queryset, filename, fields):
    """
    Output an XLS file of the queryset
    
        Usage : 
        -------
        queryset = Book.objects.all()
        fields = (
            ('Author', 'author.get_full_name'),
            ('Release date', 'release_date|date:"Y-m-d"'),
            ('Title', 'title|title')
        )
        filename = "BooksDB"
        return render_to_xls(
            queryset=queryset,
            filename=filename,
            fields=fields
        )
    """
    ezxf = xlwt.easyxf
    book = xlwt.Workbook(encoding="utf-8")
    sheet = book.add_sheet("Feuille 1")

    # Set title styles
    heading_xf = ezxf('font:name Verdana, bold on; align: wrap on, vert centre, horiz center;pattern: fore_color green ;')
    i, j = 0, 0

    # Write the titles on the first line
    for f in fields:
        sheet.write(i, j, f[0], heading_xf)
        j+=1

    for object in queryset:
        i += 1
        j = 0
        context = {'object': object}
        for f in fields:

            # I did not find yet a django stuff to 
            # deal with templatefilter
            chains = str("object.%s" % f[1]).split("|")
            var = chains[0]

            # We resolve the var to get raw data
            data = Variable(var).resolve(context)

            # If we have filters, we apply them
            # TODO : If django has a method to deal
            # with it, jsut do it
            for chain in chains[1:]:
                filter_nameargs = chain.split(':')
                filter_name = filter_nameargs[0]
                template_filter = getattr(defaultfilters, filter_name)
                if len(filter_nameargs)>1:
                    args = filter_nameargs[1].replace('"', '')
                    data = template_filter(data, args)
                else:
                    data = template_filter(data)
            
            # Finally we write the data on the sheet
            sheet.write(i, j, u"%s" % data)
            j+=1
    response = HttpResponse(mimetype='application/vnd.ms-excel')
    response['Content-Disposition'] = 'attachment; filename=%s.xls' % filename
    book.save(response)
    return response