routing.py 文件源码

def build(self, values, append_unknown=True):
        """Assembles the relative url for that rule and the subdomain.
        If building doesn't work for some reasons `None` is returned.

        :internal:
        """
        tmp = []
        add = tmp.append
        processed = set(self.arguments)
        for is_dynamic, data in self._trace:
            if is_dynamic:
                try:
                    add(self._converters[data].to_url(values[data]))
                except ValidationError:
                    return
                processed.add(data)
            else:
                add(url_quote(to_bytes(data, self.map.charset), safe='/:|+'))
        domain_part, url = (u''.join(tmp)).split(u'|', 1)

        if append_unknown:
            query_vars = MultiDict(values)
            for key in processed:
                if key in query_vars:
                    del query_vars[key]

            if query_vars:
                url += u'?' + url_encode(query_vars, charset=self.map.charset,
                                        sort=self.map.sort_parameters,
                                        key=self.map.sort_key)

        return domain_part, url