def download(self, media_id):
return self._get(<EOL>'<STR_LIT>',<EOL>params={<EOL>'<STR_LIT>': media_id<EOL>}<EOL>)<EOL>
获取临时素材
详情请参考
http://mp.weixin.qq.com/wiki/10/78b15308b053286e2a66b33f0f0f5fb6.html

:param media_id: 媒体文件 ID

:return: requests 的 Response 实例