django-modeltranslation 怎樣才能支持 zh-tw 及 zh-cn?

我用了以下代碼，在en時能正常運作。而當轉換zh-tw 及 zh-cn就出錯誤.

## keyword can't be an expression (<string>, line 1)


try:
query = Product.objects.published().select_related()
product = eval('query.get('
'slug_'+get_language()+'=slugs[-1],'
'category__slug_'+get_language()+'=slugs[-2])')
return render_to_response('products/product.html', {'product':product},
context_instance=RequestContext(request))
except: pass

query = Category.objects.select_related().all()
category = eval('get_object_or_404(query,'
'slug_'+get_language()+'=slugs[-1])')