NSO 6.1 Python API: How to get hash tag in get_object()?

[JennyW]

First of all, I went through the post Python DataCallback daemon  but my case is more complicated than this.

I have a yang module defined as

module pydp {
  namespace "http://tail-f.com/ns/example/pydp";
  prefix pydp; yang-version 1.1;

  import tailf-common {prefix tailf;}
  import ietf-inet-types {prefix inet;}

  list cont {
    key name;
    leaf name {
      type string;
    }
    container brief {
      tailf:callpoint mydp-cp;
      config false;
      leaf status {
        type string;
     }
     leaf up-time {
       type string;
     }
     list device {
       key device-name;
       leaf device-name {
         type string;
       }
       leaf mac {
         type string;
         description "MAC address of the device";
       }
     } 
     leaf-list ds-name{
        type string; 
     }
     leaf-list us-name {
       type string;
     }
  }
}

Python:

import ncs 
import _ncs 
from ncs.experimental import DataCallbacks 

def dcb_start(state): 
  dcb = DataCallbacks(state.log)
  dcb.register('/mydp:container', Handler())
  _ncs.dp.register_data_cb(state.ctx, 'mydp-cp', dcb)
  return state


def dcb_stop(start_state):
    pass


class Handler(object): 
    def get_object(self, tctx, kp, args): 
      cont_name = args.get("cont")
      with ncs.maapi.single_read_trans(tctx.uinfo.username, "passwd") as t: 
        root = ncs.maagic.get_root(t) 
        key = root.cont[device_name] 
        .... 
        return { 
          "brief": { 
            'status': 'value', 
            'up-time': 'value', 
            'device': {'device-name': 'test', 'mac': 'value'}, 
            'ds-name": ['name11', 'name12'], 
            'us-name": ['name21', 'name22'], } 


    def get_next(self, tctx, kp, args, next): 
      return None 


    def count(self): 
      return 0 


class Main(ncs.application.Application): 
  def setup(self): 
    ...
    self.register_fun(dcb_start, dcb_stop) 


  def teardown(self): 
    pass

I noticed that get_object() was invoked multiple times, guess it's because list/leaflist are supposed to be processed separately. If that's the case how can I get the hash tag from kp? I don't see class HKeyPathRef provides a method to get the hash tag. The NSO Python API is poorly documented and I couldn't find any example of using python Dp callback to implement oper commands callback. Any help will be appreciated.

Because the config/action callbacks were implemented in python, we'd like to use Python for oper callback as well.

[JennyW · Accepted solution]

Ok, I figured it out myself: use kp[idx].tag for hashed tag. For each leaflist/list one needs to return different object, in the format of {'brief': {'ds-name': ['name11', 'name12']}} (for leaflist 'ds-name').