Method _expand_help

Lib/argparse.py:682–729

(self, action)

        return result

    def _expand_help(self, action):
        help_string = self._get_help_string(action)
        if '%' not in help_string:
            return help_string
        params = dict(vars(action), prog=self._prog)
        for name in list(params):
            value = params[name]
            if value is SUPPRESS:
                del params[name]
            elif hasattr(value, '__name__'):
                params[name] = value.__name__
        if params.get('choices') is not None:
            params['choices'] = ', '.join(map(str, params['choices']))

        t = self._theme

        result = help_string % params

        if not t.reset:
            return result

        # Match format specifiers like: %s, %d, %(key)s, etc.
        fmt_spec = r'''
            %
            (?:
                %                           # %% escape
                |
                (?:\((?P<key>[^)]*)\))?     # key
                [-#0\ +]*                   # flags
                (?:\*|\d+)?                 # width
                (?:\.(?:\*|\d+))?           # precision
                [hlL]?                      # length modifier
                [diouxXeEfFgGcrsa]          # conversion type
            )
        ''&#x27;

        def colorize(match):
            spec, key = match.group(0, 'key')
            if spec == '%%':
                return '%'
            if key is not None:
                # %(key)... - format and colorize
                formatted = spec % {key: params[key]}
                return f'{t.interpolated_value}{formatted}{t.reset}'
            # bare %s etc. - format with full params dict, no colorization
            return spec % params

        return _re.sub(fmt_spec, colorize, help_string, flags=_re.VERBOSE)

    def _iter_indented_subactions(self, action):
        try: