base.py 文件源码

def find(self, base_url=None, **kwargs):
        """Find a single item with attributes matching ``**kwargs``.

        :param base_url: if provided, the generated URL will be appended to it
        """
        kwargs = self._filter_kwargs(kwargs)

        rl = self._list(
            '%(base_url)s%(query)s' % {
                'base_url': self.build_url(base_url=base_url, **kwargs),
                'query': '?%s' % parse.urlencode(kwargs) if kwargs else '',
            },
            self.collection_key)
        num = len(rl)

        if num == 0:
            msg = _("No %(name)s matching %(args)s.") % {
                'name': self.resource_class.__name__,
                'args': kwargs
            }
            raise exceptions.NotFound(404, msg)
        elif num > 1:
            raise exceptions.NoUniqueMatch
        else:
            return rl[0]