length of json object python
import json
json_data = json.dumps({
  "result":[
    {
      "run":[
        {
          "action":"stop"
        },
        {
          "action":"start"
        },
        {
          "action":"start"
        }
      ],
      "find": "true"
    }
  ]
})
item_dict = json.loads(json_data)
print len(item_dict['result'][0]['run'])