def METHOD_NAME(self, state):
    if state:
        for val in self.number_list:
            alt_txt = self['btn_' + val].property('fcode')
            self['btn_' + val].setText(alt_txt)
        for key, val in list(self.function_keys.items()):
            self['btn_' + key].KEY_CHAR = val
    else:
        self.init_numbers()