Apply Spanish layout to the pressed keys

def transform(self, keys):
        """Apply Spanish layout to the pressed keys"""
        key = keys['regular'][0]
        modifiers = keys['modifiers']

        try:
            if not modifiers:
                if key in self._letters or key in self._digits:
                    res = key
                elif key in self._command_keys:
                    res = '<' + key + '>'
                else:
                    res = self._layout['no_mods'][key]
            elif self._only_shifts(modifiers):
                if key in self._letters:
                    res = key.upper()
                else:
                    res = self._layout['shift'][key]
            elif self._only_right_alt(modifiers):
                res = self._layout['right_alt'][key]
            else:
                res = None
        except KeyError:
            res = None

        return res