python - django-mptt model instance does not support indexing -

i'm trying implement simple file browser app using django-mptt

this models.py

class rootmptt(mpttmodel):     name = models.charfield(max_length =255)     parent = treeforeignkey('self',null=true,blank=true,related_name='children',db_index=true)  class doc(models.model):     file = models.filefield(upload_to=set_upload_path_mptt)     belongs_to = models.foreignkey(rootmptt) 

i'm trying show tree view in html using code tutorial section

  {% load mptt_tags %} <ul>     {% recursetree nodes %}         <li>             {{ node.name }}             {% if not node.is_leaf_node %}                 <ul class="children">                     {{ children }}                 </ul>             {% endif %}         </li>     {% endrecursetree %} </ul> 

i'm getting below error django

'rootmptt' object not support indexing 

mainly because 'nodes' variable below

nodes = rootmptt.objects.get(pk=casenum) 

if change to

nodes = rootmptt.objects.all() 

the html rendered fine. need descendants of single node opposed root nodes.

i supposed can children getting get_children method , manually show them in html. know if theres method using recursetree

recursetree takes queryset or list of nodes, not single node. if want show 1 tree, make queryset tree in it:

nodes = rootmptt.objects.get(pk=casenum).get_descendants(include_self=true)