QFileDialog Trouble

Hi (first i want to say that sorry for my english! i speak spanish), i'm having a problem i can't solve...
After searching a lot on the web, i finally got that i can't translate a native QFileDialog directly from QT
Because i'm trying to use the OS X file dialog in Spanish, but it opens always with the buttons in english!
I read somewhere that i would tell the operating system in which language i want the Dialog!... But i don't know how to do that!
I am programming in python with pyside, but if someone has a solution on another programming language i don't have any problem with that!

Simply i want to take the native file dialog and translated to the operating system current locale

Doing QFileDialog.getOpenFileName() i get it but in english, and i want it in spanish..

Please, help! Regards!