@gen.coroutine
    def delete_attachment(self, doc, attachment_name):
        if '_rev' not in doc or '_id' not in doc:
            raise KeyError('Missing id or revision information in doc')
        else:
            url = '{0}/{1}/{2}?rev={3}'.format(
                self.db_name, url_escape(doc['_id']),
                url_escape(attachment_name), doc['_rev'])
        r = yield self._http_delete(url)
        raise gen.Return(r)
Delete a named attachment to the specified doc.
dataset/ETHPy150Open nephics/tornado-couchdb/couch/couch.py/AsyncCouch.delete_attachment