less unfortunate code

@require_http_methods(['GET'])
def list_filter(request):
    by_what = request.GET.get('by', '')
    for_what = request.GET.getlist('for', '')
    if by_what == 'date':
        try:
            dates = []
            for date in for_what:
                dates.append(datetime.strptime(date, '%m/%d/%Y'))
            rejections = Rejection.objects.filter(date__in=dates)
            title = get_title('Filter by {0} on {1}'.format(by_what, for_what[0]))
            context = {'rejections': rejections,
                       'title': title}
            return render(request, 'defective/taglist.html', context)
        except ValueError:
            return HttpResponseBadRequest('Invalid date format')
    elif by_what in ['plant',  'model',   'part',   'defect',   'qty',
                     'shift', 'station', 'rej_by', 'location', 'dispo']:
        rejections = Rejection.objects.filter(**{'{0}__in'.format(by_what): for_what})
        title = get_title('Filter by {0} for {1}'.format(by_what, ', '.join(for_what))
        context = {'rejections': rejections,
                       'title': title}
        return render(request, 'defective/taglist.html', context)