def _display_usage(self, exit=True):
        if self._usage:
            print(self._usage)
            if exit:
                sys.exit(0)

        usage_str = ''
        if self._flags:
            usage_str += '[-{}]'.format(''.join([arg.short.strip('-')
                                                for arg in self._flags]))
        if self._opts:
            usage_str += ' [{}]'.format(' '.join([' '.join([arg.short,
                                                            arg.name])
                                                 for arg in self._opts]))
        if self._req_opts:
            usage_str += ' <{}>'.format(' '.join([' '.join([arg.short,
                                                            arg.name])
                                                 for arg in self._req_opts]))
        if self._req_pos_args:
            usage_str += ' <{}>'.format(' '
                                        .join([arg.name
                                               for arg in self._req_pos_args]))
        if self._pos_args:
            usage_str += ' [{}]'.format(' '.join([arg.name
                                                 for arg in self._pos_args]))
        if self._subcmds:
            usage_str += ' [SUBCOMMANDS]'
        print('\nUSAGE:\n{} {}'.format(path.basename(self._raw_args[0]),
                                       usage_str))
        if exit:
            print('\nFor more information try --help')
            sys.exit(0)
Displays usage of app based of flags and options
dataset/ETHPy150Open kbknapp/Clapp-py/clapp/clapp.py/App._display_usage