argparser.py 文件源码

 复制代码def _check_value(self, action, value):
        """
        It's probably not a great idea to override a "hidden" method
        but the default behavior is pretty ugly and there doesn't
        seem to be any other way to change it.
        """
        # converted value must be one of the choices (if specified)
        if action.choices is not None and value not in action.choices:
            msg = ['Invalid choice, valid choices are:\n']
            for i in range(len(action.choices))[::self.ChoicesPerLine]:
                current = []
                for choice in action.choices[i:i+self.ChoicesPerLine]:
                    current.append('%-40s' % choice)
                msg.append(' | '.join(current))
            possible = get_close_matches(value, action.choices, cutoff=0.8)
            if possible:
                extra = ['\n\nInvalid choice: %r, maybe you meant:\n' % value]
                for word in possible:
                    extra.append('  * %s' % word)
                msg.extend(extra)
            raise argparse.ArgumentError(action, '\n'.join(msg))