relatively fortunate code

@require_http_methods(['GET'])
def list_filter(request):
    conversions = {'date': 'date',
                   'plant': 'plant',
                   'model': 'part__model__name',
                   'part': 'part__number',
                   'defect': 'defects__name',
                   'qty': 'quantity',
                   'shift': 'shift',
                   'station': 'station',
                   'rej_by': 'rejected_by',
                   'location': 'location',
                   'dispo': 'evaluation__disposition'}
    rejections = Rejection.objects.all()
    get_is_useful = False
    for param, val in request.GET.lists():
        if param in conversions:
            get_is_useful = True
            rejections = rejections.filter(**{conversions[param] + '__in': val})
    if get_is_useful:
        title = get_title('Filter')
        context = {'rejections': rejections,
                   'title': title}
        return render(request, 'defective/taglist.html', context)
    else:
        models = Model.objects.all()
        parts = Part.objects.all()
        defects = Defect.objects.all()
        context = {'models': models,
                   'parts': parts,
                   'defects': defects,
                   'rej': Rejection,
                   'eval': Evaluation,
                   'title': get_title('Filter')}
        return render(request, 'defective/filterform.html', context)