def __create_navigator(self, main_root):
		navigator_dir = os.path.join(main_root, 'navigator')
		safe_mkdir(navigator_dir)

		navigators = self.__config_mgr.navigator()
		self.__navigator_mgr.create_navigators(navigators, navigator_dir)
def select(cls, dataset, selection_mask=None, **selection):
        df = dataset.data
        if selection_mask is None:
            selection_mask = cls.select_mask(dataset, selection)

        indexed = cls.indexed(dataset, selection)
        if selection_mask is not None:
            df = df.loc[selection_mask]
        if indexed and len(df) == 1 and len(dataset.vdims) == 1:
            return df[dataset.vdims[0].name].iloc[0]
        return df