'Change display format'

def change_format(self):

    (format, valid) = QInputDialog.getText(self, _('Format'), _('Float    formatting'), QLineEdit.Normal, self.model.get_format())
    if valid:
        format = str(format)
        try:
            (format % 1.1)
        except:
            QMessageBox.critical(self, _('Error'), (_('Format    (%s)    is    incorrect') % format))
            return
        self.model.set_format(format)
